A surgical stapler comprises an elongate housing and a surgical staple (14) slidable longitudinally within the housing towards the free forward end thereof. The back of the staple (18) has a rearward extension (22). An actuator is slidable forwardly within the housing for driving the staple towards the free end of the housing. An upstanding flange on the extension engages a stop within the housing to restrain the back of the staple against forward movement of the actuator bends the staple to bring the free ends of the legs towards one another to close the staple. Further movement of the actuator then ruptures the join between the extension and the- back of the staple to release the closed staple.
