diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 3e384288d..3d3e4d5fb 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -3,6 +3,7 @@ import itertools
 from collections import defaultdict
 
 from boto.ec2.instance import Instance as BotoInstance, Reservation
+from boto.ec2.blockdevicemapping import BlockDeviceMapping, BlockDeviceType
 from boto.ec2.spotinstancerequest import SpotInstanceRequest as BotoSpotRequest
 from boto.ec2.launchspecification import LaunchSpecification
 
@@ -62,6 +63,9 @@ class Instance(BotoInstance, TaggedEC2Instance):
         self.subnet_id = kwargs.get("subnet_id")
         self.key_name = kwargs.get("key_name")
 
+        self.block_device_mapping = BlockDeviceMapping()
+        self.block_device_mapping['/dev/sda1'] = BlockDeviceType()
+
     @classmethod
     def create_from_cloudformation_json(cls, resource_name, cloudformation_json):
         properties = cloudformation_json['Properties']
diff --git a/moto/ec2/responses/instances.py b/moto/ec2/responses/instances.py
index 12b52607f..106702c14 100644
--- a/moto/ec2/responses/instances.py
+++ b/moto/ec2/responses/instances.py
@@ -66,7 +66,8 @@ class InstanceResponse(BaseResponse):
         return template.render(instances=instances)
 
     def describe_instance_attribute(self):
-        # TODO this and modify below should raise IncorrectInstanceState if instance not in stopped state
+        # TODO this and modify below should raise IncorrectInstanceState if
+        # instance not in stopped state
         attribute = self.querystring.get("Attribute")[0]
         key = camelcase_to_underscores(attribute)
         instance_ids = instance_ids_from_querystring(self.querystring)
@@ -76,6 +77,61 @@ class InstanceResponse(BaseResponse):
         return template.render(instance=instance, attribute=attribute, value=value)
 
     def modify_instance_attribute(self):
+        handlers = [self._dot_value_instance_attribute_handler,
+                    self._block_device_mapping_handler]
+
+        for handler in handlers:
+            success = handler()
+            if success:
+                return success
+
+        msg = "This specific call to ModifyInstanceAttribute has not been" \
+              " implemented in Moto yet. Feel free to open an issue at" \
+              " https://github.com/spulec/moto/issues"
+        raise NotImplementedError(msg)
+
+    def _block_device_mapping_handler(self):
+        """
+        Handles requests which are generated by code similar to:
+
+            instance.modify_attribute('blockDeviceMapping', {'/dev/sda1': True})
+
+        The querystring contains information similar to:
+
+            BlockDeviceMapping.1.Ebs.DeleteOnTermination : ['true']
+            BlockDeviceMapping.1.DeviceName : ['/dev/sda1']
+
+        For now we only support the "BlockDeviceMapping.1.Ebs.DeleteOnTermination"
+        configuration, but it should be trivial to add anything else.
+        """
+        mapping_counter = 1
+        mapping_device_name_fmt = 'BlockDeviceMapping.%s.DeviceName'
+        mapping_del_on_term_fmt = 'BlockDeviceMapping.%s.Ebs.DeleteOnTermination'
+
+        while True:
+            mapping_device_name = mapping_device_name_fmt % mapping_counter
+            if mapping_device_name not in self.querystring.keys():
+                break
+
+            mapping_del_on_term = mapping_del_on_term_fmt % mapping_counter
+            del_on_term_value_str = self.querystring[mapping_del_on_term][0]
+            del_on_term_value = True if 'true' == del_on_term_value_str else False
+            device_name_value = self.querystring[mapping_device_name][0]
+
+            instance_ids = instance_ids_from_querystring(self.querystring)
+            instance_id = instance_ids[0]
+            instance = ec2_backend.get_instance(instance_id)
+
+            block_device_type = instance.block_device_mapping[device_name_value]
+            block_device_type.delete_on_termination = del_on_term_value
+
+            # +1 for the next device
+            mapping_counter += 1
+
+        if mapping_counter > 1:
+            return EC2_MODIFY_INSTANCE_ATTRIBUTE
+
+    def _dot_value_instance_attribute_handler(self):
         attribute_key = None
         for key, value in self.querystring.iteritems():
             if '.Value' in key:
@@ -84,6 +140,7 @@ class InstanceResponse(BaseResponse):
 
         if not attribute_key:
             return
+
         value = self.querystring.get(attribute_key)[0]
         normalized_attribute = camelcase_to_underscores(attribute_key.split(".")[0])
         instance_ids = instance_ids_from_querystring(self.querystring)
diff --git a/tests/test_ec2/test_elastic_block_store.py b/tests/test_ec2/test_elastic_block_store.py
index c60ce0bf0..2c1edddd4 100644
--- a/tests/test_ec2/test_elastic_block_store.py
+++ b/tests/test_ec2/test_elastic_block_store.py
@@ -3,6 +3,7 @@ from boto.exception import EC2ResponseError
 import sure  # noqa
 
 from moto import mock_ec2
+from moto.ec2.models import ec2_backend
 
 
 @mock_ec2
@@ -91,4 +92,9 @@ def test_modify_attribute_blockDeviceMapping():
     reservation = conn.run_instances('ami-1234abcd')
 
     instance = reservation.instances[0]
-    instance.modify_attribute('blockDeviceMapping', {'/dev/sda1': True})
\ No newline at end of file
+
+    instance.modify_attribute('blockDeviceMapping', {'/dev/sda1': True})
+
+    instance = ec2_backend.get_instance(instance.id)
+    instance.block_device_mapping.should.have.key('/dev/sda1')
+    instance.block_device_mapping['/dev/sda1'].delete_on_termination.should.be(True)