diff --git a/tests/test_ecs/test_ecs_boto3.py b/tests/test_ecs/test_ecs_boto3.py
index e902c5d91..d671fde7d 100644
--- a/tests/test_ecs/test_ecs_boto3.py
+++ b/tests/test_ecs/test_ecs_boto3.py
@@ -1,8 +1,12 @@
 from __future__ import unicode_literals
 import boto3
 import sure  # noqa
+import json
+from moto.ec2 import utils as ec2_utils
+from uuid import UUID
 
 from moto import mock_ecs
+from moto import mock_ec2
 
 
 @mock_ecs
@@ -333,4 +337,80 @@ def test_delete_service():
     response['service']['serviceArn'].should.equal('arn:aws:ecs:us-east-1:012345678910:service/test_ecs_service')
     response['service']['serviceName'].should.equal('test_ecs_service')
     response['service']['status'].should.equal('ACTIVE')
-    response['service']['taskDefinition'].should.equal('arn:aws:ecs:us-east-1:012345678910:task-definition/test_ecs_task:1')
\ No newline at end of file
+    response['service']['taskDefinition'].should.equal('arn:aws:ecs:us-east-1:012345678910:task-definition/test_ecs_task:1')
+
+@mock_ec2
+@mock_ecs
+def test_register_container_instance():
+    ecs_client = boto3.client('ecs', region_name='us-east-1')
+    ec2 = boto3.resource('ec2', region_name='us-east-1')
+
+    test_cluster_name = 'test_ecs_cluster'
+
+    _ = ecs_client.create_cluster(
+        clusterName=test_cluster_name
+    )
+
+    test_instance = ec2.create_instances(
+        ImageId="ami-1234abcd",
+        MinCount=1,
+        MaxCount=1,
+    )[0]
+
+    instance_id_document = json.dumps(
+        ec2_utils.generate_instance_identity_document(test_instance)
+    )
+
+    response = ecs_client.register_container_instance(
+        cluster=test_cluster_name,
+        instanceIdentityDocument=instance_id_document
+    )
+
+    response['containerInstance']['ec2InstanceId'].should.equal(test_instance.id)
+    full_arn = response['containerInstance']['containerInstanceArn']
+    arn_part = full_arn.split('/')
+    arn_part[0].should.equal('arn:aws:ecs:us-east-1:012345678910:container-instance')
+    arn_part[1].should.equal(str(UUID(arn_part[1])))
+    response['containerInstance']['status'].should.equal('ACTIVE')
+    len(response['containerInstance']['registeredResources']).should.equal(0)
+    len(response['containerInstance']['remainingResources']).should.equal(0)
+    response['containerInstance']['agentConnected'].should.equal(True)
+    response['containerInstance']['versionInfo']['agentVersion'].should.equal('1.0.0')
+    response['containerInstance']['versionInfo']['agentHash'].should.equal('4023248')
+    response['containerInstance']['versionInfo']['dockerVersion'].should.equal('DockerVersion: 1.5.0')
+
+@mock_ec2
+@mock_ecs
+def test_list_container_instances():
+    ecs_client = boto3.client('ecs', region_name='us-east-1')
+    ec2 = boto3.resource('ec2', region_name='us-east-1')
+
+    test_cluster_name = 'test_ecs_cluster'
+    _ = ecs_client.create_cluster(
+        clusterName=test_cluster_name
+    )
+
+    instance_to_create = 3
+    test_instance_arns = []
+    for i in range(0, instance_to_create):
+        test_instance = ec2.create_instances(
+            ImageId="ami-1234abcd",
+            MinCount=1,
+            MaxCount=1,
+        )[0]
+
+        instance_id_document = json.dumps(
+            ec2_utils.generate_instance_identity_document(test_instance)
+        )
+
+        response = ecs_client.register_container_instance(
+            cluster=test_cluster_name,
+            instanceIdentityDocument=instance_id_document)
+
+        test_instance_arns.append(response['containerInstance']['containerInstanceArn'])
+
+    response = ecs_client.list_container_instances(cluster=test_cluster_name)
+
+    len(response['containerInstanceArns']).should.equal(instance_to_create)
+    for arn in test_instance_arns:
+        response['containerInstanceArns'].should.contain(arn)