diff --git a/google/cloud/pubsub_v1/publisher/client.py b/google/cloud/pubsub_v1/publisher/client.py
index f1de9f1f4..6a9418e69 100644
--- a/google/cloud/pubsub_v1/publisher/client.py
+++ b/google/cloud/pubsub_v1/publisher/client.py
@@ -291,6 +291,8 @@ def publish(
         Add the given message to this object; this will cause it to be
         published once the batch either has enough messages or a sufficient
         period of time has elapsed.
+        This method may block if LimitExceededBehavior.BLOCK is used in the
+        flow control settings.
 
         Example:
             >>> from google.cloud import pubsub_v1