diff --git a/mlir/python/mlir/dialects/_structured_transform_ops_ext.py b/mlir/python/mlir/dialects/_structured_transform_ops_ext.py
--- a/mlir/python/mlir/dialects/_structured_transform_ops_ext.py
+++ b/mlir/python/mlir/dialects/_structured_transform_ops_ext.py
@@ -125,7 +125,7 @@
 
 def _get_int_array_attr(values: Optional[Union[ArrayAttr, IntOrAttrList]]) -> ArrayAttr:
     if values is None:
-        return ArrayAttr.get([])
+        return None
 
     # Turn into a Python list of Python ints.
     values = _get_value_list(values)
@@ -148,7 +148,7 @@
     If the input is None, an empty ArrayAttr is returned.
     """
     if values is None:
-        return ArrayAttr.get([])
+        return None
 
     # Make sure the outer level is a list.
     values = _get_value_list(values)
@@ -493,9 +493,7 @@
         self,
         target: Union[Operation, OpView, Value],
         *,
-        padding_values: Optional[
-            Union[ArrayAttr, Sequence[Union[bool, int, float, Attribute]]]
-        ] = None,
+        padding_values: Optional[Union[ArrayAttr, Sequence[Attribute]]] = None,
         padding_dimensions: OptionalIntList = None,
         pad_to_multiple_of: OptionalIntList = None,
         pack_paddings: OptionalIntList = None,
@@ -506,17 +504,6 @@
         loc=None,
         ip=None,
     ):
-        if padding_values is None:
-            padding_values = []
-        if padding_dimensions is None:
-            padding_dimensions = []
-        if pad_to_multiple_of is None:
-            pad_to_multiple_of = []
-        if pack_paddings is None:
-            pack_paddings = []
-        if transpose_paddings is None:
-            transpose_paddings = []
-
         padding_dimensions = _get_int_array_attr(padding_dimensions)
         pad_to_multiple_of = _get_int_array_attr(pad_to_multiple_of)
         pack_paddings = _get_int_array_attr(pack_paddings)
diff --git a/mlir/test/python/dialects/transform_structured_ext.py b/mlir/test/python/dialects/transform_structured_ext.py
--- a/mlir/test/python/dialects/transform_structured_ext.py
+++ b/mlir/test/python/dialects/transform_structured_ext.py
@@ -314,14 +314,33 @@
 
 
 @run
-def testPad():
+def testPadOpNoArgs():
+    sequence = transform.SequenceOp(
+        transform.FailurePropagationMode.Propagate, [], pdl.OperationType.get()
+    )
+    with InsertionPoint(sequence.body):
+        structured.PadOp(sequence.bodyTarget)
+        transform.YieldOp()
+    # CHECK-LABEL: TEST: testPadOpNoArgs
+    # CHECK: transform.sequence
+    # CHECK: transform.structured.pad
+    # CHECK-NOT: copy_back_op
+    # CHECK-NOT: pack_paddings
+    # CHECK-NOT: pad_to_multiple_of
+    # CHECK-NOT: padding_dimensions
+    # CHECK-NOT: padding_values
+    # CHECK-NOT: transpose_paddings
+
+
+@run
+def testPadOpArgs():
     sequence = transform.SequenceOp(
         transform.FailurePropagationMode.Propagate, [], pdl.OperationType.get()
     )
     with InsertionPoint(sequence.body):
         structured.PadOp(
             sequence.bodyTarget,
-            padding_values=[FloatAttr.get_f32(42.0)],
+            padding_values=[FloatAttr.get_f32(42.0), StringAttr.get("0")],
             padding_dimensions=Attribute.parse("[1]"),
             pad_to_multiple_of=[128],
             pack_paddings=[0],
@@ -329,7 +348,7 @@
             copy_back_op="linalg.copy",
         )
         transform.YieldOp()
-    # CHECK-LABEL: TEST: testPad
+    # CHECK-LABEL: TEST: testPadOpArgs
     # CHECK: transform.sequence
     # CHECK: transform.structured.pad
     # CHECK-DAG: copy_back_op = "linalg.copy"