<p>A surgical stapler comprises an elongate housing 10 and a surgical staple 14 slidable longitudinally within the housing towards the free forward end thereof. The back 18 of the staple has a rearward extension 22. An actuator 16 is slidable forwardly within the housing for driving the staple towards the free end of the housing. An upstanding flange 30 on the extension 22 engages a stop 32 within the housing to restrain the back of the staple against forward movement ot 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.</p>