A surgical tissue retrieval instrument has a collapsible pouch at the distal end of an elongated pusher rod that is introduced into a patient's abdomen through a cannula. The instrument includes a two-jaw fork that forms a loop when in an unconstrained configuration and that supports the pouch. Deployment and operation of the fork and the pouch are controlled by a toggle means. The two jaws and the toggle means are slid in a hem surrounding the opening of the pouch when the device is assembled. An especially advantageous embodiment features two jaws of unequal length.