diff --git a/moto/sns/models.py b/moto/sns/models.py
index 4bab049b4..856255be5 100644
--- a/moto/sns/models.py
+++ b/moto/sns/models.py
@@ -256,7 +256,10 @@ class SNSBackend(BaseBackend):
         else:
             return self._get_values_nexttoken(self.subscriptions, next_token)
 
-    def publish(self, arn, message):
+    def publish(self, arn, message, subject=None):
+        if subject is not None and len(subject) >= 100:
+            raise ValueError('Subject must be less than 100 characters')
+
         try:
             topic = self.get_topic(arn)
             message_id = topic.publish(message)
diff --git a/moto/sns/responses.py b/moto/sns/responses.py
index 85764aa58..3b4aade80 100644
--- a/moto/sns/responses.py
+++ b/moto/sns/responses.py
@@ -239,6 +239,8 @@ class SNSResponse(BaseResponse):
         target_arn = self._get_param('TargetArn')
         topic_arn = self._get_param('TopicArn')
         phone_number = self._get_param('PhoneNumber')
+        subject = self._get_param('Subject')
+
         if phone_number is not None:
             # Check phone is correct syntax (e164)
             if not is_e164(phone_number):
@@ -261,7 +263,12 @@ class SNSResponse(BaseResponse):
             arn = topic_arn
 
         message = self._get_param('Message')
-        message_id = self.backend.publish(arn, message)
+
+        try:
+            message_id = self.backend.publish(arn, message, subject=subject)
+        except ValueError as err:
+            error_response = self._error('InvalidParameter', str(err))
+            return error_response, dict(status=400)
 
         if self.request_json:
             return json.dumps({
diff --git a/tests/test_sns/test_publishing_boto3.py b/tests/test_sns/test_publishing_boto3.py
index 6228f212f..1540ceb84 100644
--- a/tests/test_sns/test_publishing_boto3.py
+++ b/tests/test_sns/test_publishing_boto3.py
@@ -177,3 +177,33 @@ def test_publish_to_http():
     response = conn.publish(
         TopicArn=topic_arn, Message="my message", Subject="my subject")
     message_id = response['MessageId']
+
+
+@mock_sqs
+@mock_sns
+def test_publish_subject():
+    conn = boto3.client('sns', region_name='us-east-1')
+    conn.create_topic(Name="some-topic")
+    response = conn.list_topics()
+    topic_arn = response["Topics"][0]['TopicArn']
+
+    sqs_conn = boto3.resource('sqs', region_name='us-east-1')
+    sqs_conn.create_queue(QueueName="test-queue")
+
+    conn.subscribe(TopicArn=topic_arn,
+                   Protocol="sqs",
+                   Endpoint="arn:aws:sqs:us-east-1:123456789012:test-queue")
+    message = 'my message'
+    subject1 = 'test subject'
+    subject2 = 'test subject' * 20
+    with freeze_time("2015-01-01 12:00:00"):
+        conn.publish(TopicArn=topic_arn, Message=message, Subject=subject1)
+
+    # Just that it doesnt error is a pass
+    try:
+        with freeze_time("2015-01-01 12:00:00"):
+            conn.publish(TopicArn=topic_arn, Message=message, Subject=subject2)
+    except ClientError as err:
+        err.response['Error']['Code'].should.equal('InvalidParameter')
+    else:
+        raise RuntimeError('Should have raised an InvalidParameter exception')