diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index e78137ca..4bec04af 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -2,6 +2,7 @@ from __future__ import unicode_literals
 import copy
 import itertools
 from collections import defaultdict
+from datetime import datetime
 
 import six
 import boto
@@ -96,6 +97,11 @@ class InstanceState(object):
         self.name = name
         self.code = code
 
+class StateReason(object):
+    def __init__(self, message="", code=""):
+        self.message = message
+        self.code = code
+
 
 class TaggedEC2Resource(object):
     def get_tags(self, *args, **kwargs):
@@ -259,6 +265,8 @@ class Instance(BotoInstance, TaggedEC2Resource):
         self.id = random_instance_id()
         self.image_id = image_id
         self._state = InstanceState("running", 16)
+        self._reason = ""
+        self._state_reason = StateReason()
         self.user_data = user_data
         self.security_groups = security_groups
         self.instance_type = kwargs.get("instance_type", "m1.small")
@@ -318,6 +326,9 @@ class Instance(BotoInstance, TaggedEC2Resource):
         self._state.name = "running"
         self._state.code = 16
 
+        self._reason = ""
+        self._state_reason = StateReason()
+
     def stop(self, *args, **kwargs):
         for nic in self.nics.values():
             nic.stop()
@@ -325,6 +336,10 @@ class Instance(BotoInstance, TaggedEC2Resource):
         self._state.name = "stopped"
         self._state.code = 80
 
+        self._reason = "User initiated ({0})".format(datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S UTC'))
+        self._state_reason = StateReason("Client.UserInitiatedShutdown: User initiated shutdown",
+                                         "Client.UserInitiatedShutdown")
+
     def terminate(self, *args, **kwargs):
         for nic in self.nics.values():
             nic.stop()
@@ -332,10 +347,17 @@ class Instance(BotoInstance, TaggedEC2Resource):
         self._state.name = "terminated"
         self._state.code = 48
 
+        self._reason = "User initiated ({0})".format(datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S UTC'))
+        self._state_reason = StateReason("Client.UserInitiatedShutdown: User initiated shutdown",
+                                         "Client.UserInitiatedShutdown")
+
     def reboot(self, *args, **kwargs):
         self._state.name = "running"
         self._state.code = 16
 
+        self._reason = ""
+        self._state_reason = StateReason()
+
     def get_tags(self):
         tags = ec2_backend.describe_tags(filters={'resource-id': [self.id]})
         return tags
diff --git a/moto/ec2/responses/instances.py b/moto/ec2/responses/instances.py
index b1833ee2..70f19a8f 100644
--- a/moto/ec2/responses/instances.py
+++ b/moto/ec2/responses/instances.py
@@ -303,7 +303,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns='http://ec2.amazona
                     </instanceState>
                     <privateDnsName>ip-10.0.0.12.ec2.internal</privateDnsName>
                     <dnsName>ec2-46.51.219.63.compute-1.amazonaws.com</dnsName>
-                    <reason/>
+                    <reason>{{ instance._reason }}</reason>
                     <keyName>{{ instance.key_name }}</keyName>
                     <amiLaunchIndex>0</amiLaunchIndex>
                     <productCodes/>
@@ -337,6 +337,10 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns='http://ec2.amazona
                       </item>
                       {% endfor %}
                     </groupSet>
+                    <stateReason>
+                      <code>{{ instance._state_reason.code }}</code>
+                      <message>{{ instance._state_reason.message }}</message>
+                    </stateReason>
                     <architecture>{{ instance.architecture }}</architecture>
                     <kernelId>{{ instance.kernel }}</kernelId>
                     <rootDeviceType>ebs</rootDeviceType>
diff --git a/moto/ec2/utils.py b/moto/ec2/utils.py
index e16a6935..7251ff0b 100644
--- a/moto/ec2/utils.py
+++ b/moto/ec2/utils.py
@@ -271,15 +271,27 @@ def keypair_names_from_querystring(querystring_dict):
 
 filter_dict_attribute_mapping = {
     'instance-state-name': 'state',
-    'instance-id': 'id'
+    'instance-id': 'id',
+    'state-reason-code': '_state_reason.code',
 }
 
+def get_instance_value(instance, instance_attr):
+    keys = instance_attr.split('.')
+    val = instance
+    for key in keys:
+        if hasattr(val, key):
+            val = getattr(val, key)
+        elif isinstance(val, dict):
+            val = val[key]
+        else:
+            return None
+    return val
 
 def passes_filter_dict(instance, filter_dict):
     for filter_name, filter_values in filter_dict.items():
         if filter_name in filter_dict_attribute_mapping:
             instance_attr = filter_dict_attribute_mapping[filter_name]
-            instance_value = getattr(instance, instance_attr)
+            instance_value = get_instance_value(instance, instance_attr)
             if instance_value not in filter_values:
                 return False
         elif filter_name.startswith('tag:'):
diff --git a/tests/test_ec2/test_instances.py b/tests/test_ec2/test_instances.py
index bc6938e8..955ce047 100644
--- a/tests/test_ec2/test_instances.py
+++ b/tests/test_ec2/test_instances.py
@@ -135,6 +135,24 @@ def test_get_instances_filtering_by_instance_id():
     reservations = conn.get_all_instances(filters={'instance-id': 'non-existing-id'})
     reservations.should.have.length_of(0)
 
+@mock_ec2
+def test_get_instances_filtering_by_reason_code():
+    conn = boto.connect_ec2()
+    reservation = conn.run_instances('ami-1234abcd', min_count=3)
+    instance1, instance2, instance3 = reservation.instances
+    instance1.stop()
+    instance2.terminate()
+
+    reservations = conn.get_all_instances(filters={'state-reason-code': 'Client.UserInitiatedShutdown'})
+    # get_all_instances should return instance1 and instance2
+    reservations[0].instances.should.have.length_of(2)
+    set([instance1.id, instance2.id]).should.equal(set([i.id for i in reservations[0].instances]))
+
+    reservations = conn.get_all_instances(filters={'state-reason-code': ''})
+    # get_all_instances should return instance 3
+    reservations[0].instances.should.have.length_of(1)
+    reservations[0].instances[0].id.should.equal(instance3.id)
+
 @mock_ec2
 def test_get_instances_filtering_by_tag():
     conn = boto.connect_ec2()