A surgical stapler comprising at least one cam having a cam surface, an arrangement for actuating the cam for a longitudinal firing movement of the cam surface, a cartridge having a plurality of staple drive members driven by the longitudinal movement of the cam surface, and a plurality of surgical staples respectively associated with the staple drive members for being fired by the longitudinal movement of the cam surface. In one embodiment of the present invention, the staple drive members include at least a pair of alternating first and second staple drive members, the first staple drive member including a laterally spaced pair of staple driving surfaces, the second staple drive member including a single staple driving surface. The first and second staple drive members are disposed such that the staple driving surfaces thereof are arranged in laterally spaced three rows. Alternate embodiments include drive members each having a pair of longitudinally aligned driving surfaces, and a third laterally offset driving surface, as well as a spine-like flexible drive element operatively positioned between the cam surface of the cam and the drive members.