diff --git a/src/BulkWriteResult.php b/src/BulkWriteResult.php
new file mode 100644
index 000000000..2862a59cd
--- /dev/null
+++ b/src/BulkWriteResult.php
@@ -0,0 +1,136 @@
+<?php
+
+namespace MongoDB;
+
+use BSON\ObjectId;
+use MongoDB\Driver\WriteResult;
+
+/**
+ * Result class for a bulk write operation.
+ */
+class BulkWriteResult
+{
+    private $writeResult;
+    private $insertedIds;
+
+    /**
+     * Constructor.
+     *
+     * @param WriteResult $writeResult
+     * @param mixed[]     $insertedIds
+     */
+    public function __construct(WriteResult $writeResult, array $insertedIds)
+    {
+        $this->writeResult = $writeResult;
+        $this->insertedIds = $insertedIds;
+    }
+
+    /**
+     * Return the number of documents that were deleted.
+     *
+     * This value is undefined if the write was not acknowledged.
+     *
+     * @see BulkWriteResult::isAcknowledged()
+     * @return integer
+     */
+    public function getDeletedCount()
+    {
+        return $this->writeResult->getDeletedCount();
+    }
+
+    /**
+     * Return the number of documents that were inserted.
+     *
+     * This value is undefined if the write was not acknowledged.
+     *
+     * @see BulkWriteResult::isAcknowledged()
+     * @return integer
+     */
+    public function getInsertedCount()
+    {
+        return $this->writeResult->getInsertedCount();
+    }
+
+    /**
+     * Return a map of the inserted documents' IDs.
+     *
+     * The index of each ID in the map corresponds to the document's position
+     * in bulk operation. If the document had an ID prior to insertion (i.e. the
+     * driver did not generate an ID), this will contain its "_id" field value.
+     * Any driver-generated ID will be an MongoDB\Driver\ObjectID instance.
+     *
+     * @return mixed[]
+     */
+    public function getInsertedIds()
+    {
+        return $this->insertedIds;
+    }
+
+    /**
+     * Return the number of documents that were matched by the filter.
+     *
+     * This value is undefined if the write was not acknowledged.
+     *
+     * @see BulkWriteResult::isAcknowledged()
+     * @return integer
+     */
+    public function getMatchedCount()
+    {
+        return $this->writeResult->getMatchedCount();
+    }
+
+    /**
+     * Return the number of documents that were modified.
+     *
+     * This value is undefined if the write was not acknowledged or if the write
+     * executed as a legacy operation instead of write command.
+     *
+     * @see BulkWriteResult::isAcknowledged()
+     * @return integer|null
+     */
+    public function getModifiedCount()
+    {
+        return $this->writeResult->getModifiedCount();
+    }
+
+    /**
+     * Return the number of documents that were upserted.
+     *
+     * This value is undefined if the write was not acknowledged.
+     *
+     * @see BulkWriteResult::isAcknowledged()
+     * @return integer
+     */
+    public function getUpsertedCount()
+    {
+        return $this->writeResult->getUpsertedCount();
+    }
+
+    /**
+     * Return a map of the upserted documents' IDs.
+     *
+     * The index of each ID in the map corresponds to the document's position
+     * in bulk operation. If the document had an ID prior to upserting (i.e. the
+     * server did not need to generate an ID), this will contain its "_id". Any
+     * server-generated ID will be an MongoDB\Driver\ObjectID instance.
+     *
+     * @return mixed[]
+     */
+    public function getUpsertedIds()
+    {
+        return $this->writeResult->getUpsertedIds();
+    }
+
+    /**
+     * Return whether this update was acknowledged by the server.
+     *
+     * If the update was not acknowledged, other fields from the WriteResult
+     * (e.g. matchedCount) will be undefined.
+     *
+     * @return boolean
+     */
+    public function isAcknowledged()
+    {
+        return $this->writeResult->isAcknowledged();
+    }
+}
diff --git a/src/Collection.php b/src/Collection.php
index a3cddee23..8e079bae1 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -198,17 +198,18 @@ function (\stdClass $document) { return (array) $document; },
      *
      * @see Collection::getBulkOptions() for supported $options
      *
-     * @param array $bulk    Array of operations
+     * @param array $ops    Array of operations
      * @param array $options Additional options
      * @return WriteResult
      */
-    public function bulkWrite(array $bulk, array $options = array())
+    public function bulkWrite(array $ops, array $options = array())
     {
         $options = array_merge($this->getBulkOptions(), $options);
 
         $bulk = new BulkWrite($options["ordered"]);
+        $insertedIds = array();
 
-        foreach ($bulk as $n => $op) {
+        foreach ($ops as $n => $op) {
             foreach ($op as $opname => $args) {
                 if (!isset($args[0])) {
                     throw new InvalidArgumentException(sprintf("Missing argument#1 for '%s' (operation#%d)", $opname, $n));
@@ -216,14 +217,25 @@ public function bulkWrite(array $bulk, array $options = array())
 
                 switch ($opname) {
                 case "insertOne":
-                    $bulk->insert($args[0]);
+                    $insertedId = $bulk->insert($args[0]);
+
+                    if ($insertedId !== null) {
+                        $insertedIds[$n] = $insertedId;
+                    } else {
+                        $insertedIds[$n] = is_array($args[0]) ? $args[0]['_id'] : $args[0]->_id;
+                    }
+
                     break;
 
                 case "updateMany":
                     if (!isset($args[1])) {
                         throw new InvalidArgumentException(sprintf("Missing argument#2 for '%s' (operation#%d)", $opname, $n));
                     }
-                    $options = array_merge($this->getWriteOptions(), isset($args[2]) ? $args[2] : array(), array("limit" => 0));
+                    $options = array_merge($this->getWriteOptions(), isset($args[2]) ? $args[2] : array(), array("multi" => true));
+                    $firstKey = key($args[1]);
+                    if (!isset($firstKey[0]) || $firstKey[0] != '$') {
+                        throw new InvalidArgumentException("First key in \$update must be a \$operator");
+                    }
 
                     $bulk->update($args[0], $args[1], $options);
                     break;
@@ -232,7 +244,7 @@ public function bulkWrite(array $bulk, array $options = array())
                     if (!isset($args[1])) {
                         throw new InvalidArgumentException(sprintf("Missing argument#2 for '%s' (operation#%d)", $opname, $n));
                     }
-                    $options = array_merge($this->getWriteOptions(), isset($args[2]) ? $args[2] : array(), array("limit" => 1));
+                    $options = array_merge($this->getWriteOptions(), isset($args[2]) ? $args[2] : array(), array("multi" => false));
                     $firstKey = key($args[1]);
                     if (!isset($firstKey[0]) || $firstKey[0] != '$') {
                         throw new InvalidArgumentException("First key in \$update must be a \$operator");
@@ -245,7 +257,7 @@ public function bulkWrite(array $bulk, array $options = array())
                     if (!isset($args[1])) {
                         throw new InvalidArgumentException(sprintf("Missing argument#2 for '%s' (operation#%d)", $opname, $n));
                     }
-                    $options = array_merge($this->getWriteOptions(), isset($args[2]) ? $args[2] : array(), array("limit" => 1));
+                    $options = array_merge($this->getWriteOptions(), isset($args[2]) ? $args[2] : array(), array("multi" => false));
                     $firstKey = key($args[1]);
                     if (isset($firstKey[0]) && $firstKey[0] == '$') {
                         throw new InvalidArgumentException("First key in \$update must NOT be a \$operator");
@@ -269,7 +281,10 @@ public function bulkWrite(array $bulk, array $options = array())
                 }
             }
         }
-        return $this->manager->executeBulkWrite($this->ns, $bulk, $this->wc);
+
+        $writeResult = $this->manager->executeBulkWrite($this->ns, $bulk, $this->wc);
+
+        return new BulkWriteResult($writeResult, $insertedIds);
     }
 
     /**
diff --git a/src/InsertManyResult.php b/src/InsertManyResult.php
index e7401b541..14c9f41c1 100644
--- a/src/InsertManyResult.php
+++ b/src/InsertManyResult.php
@@ -18,7 +18,7 @@ class InsertManyResult
      * @param WriteResult $writeResult
      * @param mixed[]     $insertedIds
      */
-    public function __construct(WriteResult $writeResult, array $insertedIds = array())
+    public function __construct(WriteResult $writeResult, array $insertedIds)
     {
         $this->writeResult = $writeResult;
         $this->insertedIds = $insertedIds;
@@ -38,11 +38,11 @@ public function getInsertedCount()
     }
 
     /**
-     * Return the map of inserted IDs that were generated by the driver.
+     * Return a map of the inserted documents' IDs.
      *
      * The index of each ID in the map corresponds to the document's position
-     * in bulk operation. If the document already an ID prior to insertion (i.e.
-     * the driver did not need to generate an ID), this will contain its "_id".
+     * in bulk operation. If the document had an ID prior to insertion (i.e. the
+     * driver did not generate an ID), this will contain its "_id" field value.
      * Any driver-generated ID will be an MongoDB\Driver\ObjectID instance.
      *
      * @return mixed[]
diff --git a/src/InsertOneResult.php b/src/InsertOneResult.php
index fc377e999..416f77401 100644
--- a/src/InsertOneResult.php
+++ b/src/InsertOneResult.php
@@ -38,7 +38,7 @@ public function getInsertedCount()
     }
 
     /**
-     * Return the inserted ID that was generated by the driver.
+     * Return the inserted document's ID.
      *
      * If the document already an ID prior to insertion (i.e. the driver did not
      * need to generate an ID), this will contain its "_id". Any
diff --git a/src/UpdateResult.php b/src/UpdateResult.php
index 8df698478..78dd8f014 100644
--- a/src/UpdateResult.php
+++ b/src/UpdateResult.php
@@ -2,7 +2,6 @@
 
 namespace MongoDB;
 
-use BSON\ObjectId;
 use MongoDB\Driver\WriteResult;
 
 /**
@@ -38,7 +37,8 @@ public function getMatchedCount()
     /**
      * Return the number of documents that were modified.
      *
-     * This value is undefined if the write was not acknowledged.
+     * This value is undefined if the write was not acknowledged or if the write
+     * executed as a legacy operation instead of write command.
      *
      * @see UpdateResult::isAcknowledged()
      * @return integer
@@ -48,12 +48,25 @@ public function getModifiedCount()
         return $this->writeResult->getModifiedCount();
     }
 
+    /**
+     * Return the number of documents that were upserted.
+     *
+     * This value is undefined if the write was not acknowledged.
+     *
+     * @see UpdateResult::isAcknowledged()
+     * @return integer
+     */
+    public function getUpsertedCount()
+    {
+        return $this->writeResult->getUpsertedCount();
+    }
+
     /**
      * Return the ID of the document inserted by an upsert operation.
      *
      * This value is undefined if an upsert did not take place.
      *
-     * @return ObjectId|null
+     * @return mixed|null
      */
     public function getUpsertedId()
     {
diff --git a/tests/Collection/BulkWriteFunctionalTest.php b/tests/Collection/BulkWriteFunctionalTest.php
new file mode 100644
index 000000000..73a913732
--- /dev/null
+++ b/tests/Collection/BulkWriteFunctionalTest.php
@@ -0,0 +1,218 @@
+<?php
+
+namespace MongoDB\Tests\Collection;
+
+use MongoDB\Driver\BulkWrite;
+
+class BulkWriteFunctionalTest extends FunctionalTestCase
+{
+    private $omitModifiedCount;
+
+    public function setUp()
+    {
+        parent::setUp();
+
+        $this->omitModifiedCount = version_compare($this->getServerVersion(), '2.6.0', '<');
+    }
+
+    public function testInserts()
+    {
+        $ops = array(
+            array('insertOne' => array(array('_id' => 1, 'x' => 11))),
+            array('insertOne' => array(array('x' => 22))),
+        );
+
+        $result = $this->collection->bulkWrite($ops);
+        $this->assertInstanceOf('MongoDB\BulkWriteResult', $result);
+        $this->assertSame(2, $result->getInsertedCount());
+
+        $insertedIds = $result->getInsertedIds();
+        $this->assertSame(1, $insertedIds[0]);
+        $this->assertInstanceOf('BSON\ObjectId', $insertedIds[1]);
+
+        $expected = array(
+            array('_id' => $insertedIds[0], 'x' => 11),
+            array('_id' => $insertedIds[1], 'x' => 22),
+        );
+
+        $this->assertEquals($expected, $this->collection->find()->toArray());
+    }
+
+    public function testUpdates()
+    {
+        $this->createFixtures(4);
+
+        $ops = array(
+            array('updateOne' => array(array('_id' => 2), array('$inc' => array('x' => 1)))),
+            array('updateMany' => array(array('_id' => array('$gt' => 2)), array('$inc' => array('x' => -1)))),
+            array('updateOne' => array(array('_id' => 5), array('$set' => array('x' => 55)), array('upsert' => true))),
+            array('updateOne' => array(array('x' => 66), array('$set' => array('x' => 66)), array('upsert' => true))),
+            array('updateMany' => array(array('x' => array('$gt' => 50)), array('$inc' => array('x' => 1)))),
+        );
+
+        $result = $this->collection->bulkWrite($ops);
+        $this->assertInstanceOf('MongoDB\BulkWriteResult', $result);
+        $this->assertSame(5, $result->getMatchedCount());
+        $this->omitModifiedCount or $this->assertSame(5, $result->getModifiedCount());
+        $this->assertSame(2, $result->getUpsertedCount());
+
+        $upsertedIds = $result->getUpsertedIds();
+        $this->assertSame(5, $upsertedIds[2]);
+        $this->assertInstanceOf('BSON\ObjectId', $upsertedIds[3]);
+
+        $expected = array(
+            array('_id' => 1, 'x' => 11),
+            array('_id' => 2, 'x' => 23),
+            array('_id' => 3, 'x' => 32),
+            array('_id' => 4, 'x' => 43),
+            array('_id' => 5, 'x' => 56),
+            array('_id' => $upsertedIds[3], 'x' => 67),
+        );
+
+        $this->assertEquals($expected, $this->collection->find()->toArray());
+    }
+
+    public function testDeletes()
+    {
+        $this->createFixtures(4);
+
+        $ops = array(
+            array('deleteOne' => array(array('_id' => 1))),
+            array('deleteMany' => array(array('_id' => array('$gt' => 2)))),
+        );
+
+        $result = $this->collection->bulkWrite($ops);
+        $this->assertInstanceOf('MongoDB\BulkWriteResult', $result);
+        $this->assertSame(3, $result->getDeletedCount());
+
+        $expected = array(
+            array('_id' => 2, 'x' => 22),
+        );
+
+        $this->assertEquals($expected, $this->collection->find()->toArray());
+    }
+
+    public function testMixedOrderedOperations()
+    {
+        $this->createFixtures(3);
+
+        $ops = array(
+            array('updateOne' => array(array('_id' => array('$gt' => 1)), array('$inc' => array('x' => 1)))),
+            array('updateMany' => array(array('_id' => array('$gt' => 1)), array('$inc' => array('x' => 1)))),
+            array('insertOne' => array(array('_id' => 4, 'x' => 44))),
+            array('deleteMany' => array(array('x' => array('$nin' => array(24, 34))))),
+            array('replaceOne' => array(array('_id' => 4), array('_id' => 4, 'x' => 44), array('upsert' => true))),
+        );
+
+        $result = $this->collection->bulkWrite($ops);
+        $this->assertInstanceOf('MongoDB\BulkWriteResult', $result);
+
+        $this->assertSame(1, $result->getInsertedCount());
+        $this->assertSame(array(2 => 4), $result->getInsertedIds());
+
+        $this->assertSame(3, $result->getMatchedCount());
+        $this->omitModifiedCount or $this->assertSame(3, $result->getModifiedCount());
+        $this->assertSame(1, $result->getUpsertedCount());
+        $this->assertSame(array(4 => 4), $result->getUpsertedIds());
+
+        $this->assertSame(2, $result->getDeletedCount());
+
+        $expected = array(
+            array('_id' => 2, 'x' => 24),
+            array('_id' => 3, 'x' => 34),
+            array('_id' => 4, 'x' => 44),
+        );
+
+        $this->assertEquals($expected, $this->collection->find()->toArray());
+    }
+
+    /**
+     * @expectedException MongoDB\Exception\InvalidArgumentException
+     * @expectedExceptionMessage Unknown operation type called 'foo' (operation#0)
+     */
+    public function testUnknownOperation()
+    {
+        $this->collection->bulkWrite(array(
+            array('foo' => array(array('_id' => 1))),
+        ));
+    }
+
+    /**
+     * @expectedException MongoDB\Exception\InvalidArgumentException
+     * @expectedExceptionMessageRegExp /Missing argument#\d+ for '\w+' \(operation#\d+\)/
+     * @dataProvider provideOpsWithMissingArguments
+     */
+    public function testMissingArguments(array $ops)
+    {
+        $this->collection->bulkWrite($ops);
+    }
+
+    public function provideOpsWithMissingArguments()
+    {
+        return array(
+            array(array(array('insertOne' => array()))),
+            array(array(array('updateOne' => array()))),
+            array(array(array('updateOne' => array(array('_id' => 1))))),
+            array(array(array('updateMany' => array()))),
+            array(array(array('updateMany' => array(array('_id' => 1))))),
+            array(array(array('replaceOne' => array()))),
+            array(array(array('replaceOne' => array(array('_id' => 1))))),
+            array(array(array('deleteOne' => array()))),
+            array(array(array('deleteMany' => array()))),
+        );
+    }
+
+    /**
+     * @expectedException MongoDB\Exception\InvalidArgumentException
+     * @expectedExceptionMessage First key in $update must be a $operator
+     */
+    public function testUpdateOneRequiresUpdateOperators()
+    {
+        $this->collection->bulkWrite(array(
+            array('updateOne' => array(array('_id' => 1), array('x' => 1))),
+        ));
+    }
+
+    /**
+     * @expectedException MongoDB\Exception\InvalidArgumentException
+     * @expectedExceptionMessage First key in $update must be a $operator
+     */
+    public function testUpdateManyRequiresUpdateOperators()
+    {
+        $this->collection->bulkWrite(array(
+            array('updateMany' => array(array('_id' => array('$gt' => 1)), array('x' => 1))),
+        ));
+    }
+
+    /**
+     * @expectedException MongoDB\Exception\InvalidArgumentException
+     * @expectedExceptionMessage First key in $update must NOT be a $operator
+     */
+    public function testReplaceOneRequiresReplacementDocument()
+    {
+        $this->collection->bulkWrite(array(
+            array('replaceOne' => array(array('_id' => 1), array('$inc' => array('x' => 1)))),
+        ));
+    }
+
+    /**
+     * Create data fixtures.
+     *
+     * @param integer $n
+     */
+    private function createFixtures($n)
+    {
+        $bulkWrite = new BulkWrite(true);
+
+        for ($i = 1; $i <= $n; $i++) {
+            $bulkWrite->insert(array(
+                '_id' => $i,
+                'x' => (integer) ($i . $i),
+            ));
+        }
+
+        $result = $this->manager->executeBulkWrite($this->getNamespace(), $bulkWrite);
+
+        $this->assertEquals($n, $result->getInsertedCount());
+    }
+}
\ No newline at end of file