diff --git a/python/pyspark/mllib/clustering.py b/python/pyspark/mllib/clustering.py
index 12081f8c6907..1fa061dc2da9 100644
--- a/python/pyspark/mllib/clustering.py
+++ b/python/pyspark/mllib/clustering.py
@@ -734,6 +734,12 @@ def describeTopics(self, maxTermsPerTopic=None):
         """Return the topics described by weighted terms.
 
         WARNING: If vocabSize and k are large, this can return a large object!
+
+        :param maxTermsPerTopic: Maximum number of terms to collect for each topic.
+            (default: vocabulary size)
+        :return: Array over topics. Each topic is represented as a pair of matching arrays:
+            (term indices, term weights in topic).
+            Each topic's terms are sorted in order of decreasing weight.
         """
         if maxTermsPerTopic is None:
             topics = self.call("describeTopics")