diff --git a/pydantic/_internal/_generate_schema.py b/pydantic/_internal/_generate_schema.py
index 8f2f19391b..63ef885919 100644
--- a/pydantic/_internal/_generate_schema.py
+++ b/pydantic/_internal/_generate_schema.py
@@ -1130,7 +1130,9 @@ def _namedtuple_schema(self, namedtuple_cls: Any, origin: Any) -> core_schema.Co
 
             arguments_schema = core_schema.arguments_schema(
                 [
-                    self._generate_parameter_schema(field_name, annotation)
+                    self._generate_parameter_schema(
+                        field_name, annotation, default=namedtuple_cls._field_defaults.get(field_name, Parameter.empty)
+                    )
                     for field_name, annotation in annotations.items()
                 ],
                 metadata=build_metadata_dict(js_prefer_positional_arguments=True),
diff --git a/tests/test_types_namedtuple.py b/tests/test_types_namedtuple.py
index 39a350f468..92302f4bca 100644
--- a/tests/test_types_namedtuple.py
+++ b/tests/test_types_namedtuple.py
@@ -199,3 +199,12 @@ class MyNamedTuple(TypingExtensionsNamedTuple, Generic[T]):
             'type': 'int_parsing',
         }
     ]
+
+
+def test_namedtuple_defaults():
+    class NT(NamedTuple):
+        x: int
+        y: int = 33
+
+    assert TypeAdapter(NT).validate_python([1]) == (1, 33)
+    assert TypeAdapter(NT).validate_python({'x': 22}) == (22, 33)