diff --git a/moto/iam/models.py b/moto/iam/models.py
index 2a76e9126..1110da682 100644
--- a/moto/iam/models.py
+++ b/moto/iam/models.py
@@ -719,7 +719,7 @@ class AccountPasswordPolicy(BaseModel):
 
     def _format_error(self, key, value, constraint):
         return 'Value "{value}" at "{key}" failed to satisfy constraint: {constraint}'.format(
-            constraint=constraint, key=key, value=value,
+            constraint=constraint, key=key, value=value
         )
 
     def _raise_errors(self):
@@ -731,7 +731,7 @@ class AccountPasswordPolicy(BaseModel):
 
             raise ValidationError(
                 "{count} validation error{plural} detected: {errors}".format(
-                    count=count, plural=plural, errors=errors,
+                    count=count, plural=plural, errors=errors
                 )
             )
 
@@ -1104,11 +1104,17 @@ class IAMBackend(BaseBackend):
         raise IAMNotFoundException("Policy not found")
 
     def create_instance_profile(self, name, path, role_ids):
+        if self.instance_profiles.get(name):
+            raise IAMConflictException(
+                code="EntityAlreadyExists",
+                message="Instance Profile {0} already exists.".format(name),
+            )
+
         instance_profile_id = random_resource_id()
 
         roles = [iam_backend.get_role_by_id(role_id) for role_id in role_ids]
         instance_profile = InstanceProfile(instance_profile_id, name, path, roles)
-        self.instance_profiles[instance_profile_id] = instance_profile
+        self.instance_profiles[name] = instance_profile
         return instance_profile
 
     def get_instance_profile(self, profile_name):
diff --git a/tests/test_iam/test_iam.py b/tests/test_iam/test_iam.py
index e0d8fdb82..8eea201d0 100644
--- a/tests/test_iam/test_iam.py
+++ b/tests/test_iam/test_iam.py
@@ -169,6 +169,14 @@ def test_create_role_and_instance_profile():
     profile.path.should.equal("/")
 
 
+@mock_iam
+def test_create_instance_profile_should_throw_when_name_is_not_unique():
+    conn = boto3.client("iam", region_name="us-east-1")
+    conn.create_instance_profile(InstanceProfileName="unique-instance-profile")
+    with assert_raises(ClientError):
+        conn.create_instance_profile(InstanceProfileName="unique-instance-profile")
+
+
 @mock_iam_deprecated()
 def test_remove_role_from_instance_profile():
     conn = boto.connect_iam()