A laparoscopic surgical access device comprises a first frame and a second frame having relative axial positions. A flexible and resilient iris valve is connected to the first and second frames and has a closed position and an opened position based on the relative angular position of the first and second frames. A lock is connected to the first and second frames, the lock being selectively operative to prevent relative rotational movement in a first rotational direction. One embodiment uses a ratchet and pawl mechanism operable with a control ring. Another embodiment uses a ratchet and pawl mechanism operable with a button. Yet another embodiment uses a wedge track and ball mechanism.
