Abstract: A surgical trocar access sheath having a laterally expandable retention mechanism for percutaneous insertion through a body cavity wall. The expandable retention mechanism is positioned about the distal end of the sheath for retaining the access sheath within the body cavity. The access sheath has an inner elongated member cannula and an outer elongated member tube having a slick surface for ready insertion through a puncture site. The laterally expandable retention mechanism includes a plurality of strips extending and formed longitudinally in the outer tube. The retention mechanism has an expanded state and a retracted state. In the expanded state, the longitudinal strips extend radially from the outer elongated member tube to engage the interior surface of the body cavity wall. The expandable retention mechanism is actuated by sliding an actuating mechanism hub attached to the distal end of the outer elongated member tube against another hub fixedly attached to the inner elongated member cannula.