diff --git a/python/cudf/cudf/core/series.py b/python/cudf/cudf/core/series.py
index 413fcefc2bc..f786853b3f4 100644
--- a/python/cudf/cudf/core/series.py
+++ b/python/cudf/cudf/core/series.py
@@ -845,6 +845,11 @@ def set_mask(self, mask, null_count=None):
         4       5
         dtype: int64
         """
+        warnings.warn(
+            "Series.set_mask is deprecated and will be removed "
+            "in the future.",
+            DeprecationWarning,
+        )
         col = self._column.set_mask(mask)
         return self._copy_construct(data=col)