A surgical fastener applying apparatus, comprising: a motorized handle assembly having an elongated member extending therefrom; an end effector assembly operably disposed at the end of the elongated member, the end effector including an anvil assembly and a cartridge assembly, at least one of the anvil assembly and the cartridge assembly movable relative to the other between an open position and a closed position for grasping tissue therebetween, the cartridge assembly configured to retain a plurality of surgical fasteners therein; a fluid-actuated drive assembly including a proximal piston assembly provided in the handle assembly, and an elongated fluid tube coupling the proximal piston assembly to a distal piston assembly, the elongated tube substantially filled with a fluid such that oscillation of the proximal piston assembly between first and second positions effects oscillation of the distal piston assembly between proximal and distal positions, the distal piston assembly being housed in a tool assembly of the end effector and including a distal piston member configured to oscillate between the proximal and distal positions, the distal piston member including a base and a rack extending distally from the base, the rack slidably disposed within the cartridge assembly; a motor assembly housed with the handle assembly and being coupled to the proximal piston assembly and configured to drive the proximal piston assembly to oscillate between the first and second positions; a drive beam configured for translation through the cartridge assembly to eject the plurality of surgical fasteners from the cartridge assembly; a pawl assembly coupling the drive beam to the rack such that the drive beam is incrementally advanced along the rack and through the cartridge assembly as the distal piston member oscillates between the proximal position and the distal position; and a retraction assembly coupled to the drive beam and the pawl assembly, the retraction assembly selectively actuatable for translating the drive beam proximally through the cartridge assembly, the retraction assembly including a retraction cord coupled to the drive beam and the pawl assembly at a first end thereof and having a retraction knob disposed at a second end thereof. a motorized handle assembly having an elongated member extending therefrom; an end effector assembly operably disposed at the end of the elongated member, the end effector including an anvil assembly and a cartridge assembly, at least one of the anvil assembly and the cartridge assembly movable relative to the other between an open position and a closed position for grasping tissue therebetween, the cartridge assembly configured to retain a plurality of surgical fasteners therein; a fluid-actuated drive assembly including a proximal piston assembly provided in the handle assembly, and an elongated fluid tube coupling the proximal piston assembly to a distal piston assembly, the elongated tube substantially filled with a fluid such that oscillation of the proximal piston assembly between first and second positions effects oscillation of the distal piston assembly between proximal and distal positions, the distal piston assembly being housed in a tool assembly of the end effector and including a distal piston member configured to oscillate between the proximal and distal positions, the distal piston member including a base and a rack extending distally from the base, the rack slidably disposed within the cartridge assembly; a motor assembly housed with the handle assembly and being coupled to the proximal piston assembly and configured to drive the proximal piston assembly to oscillate between the first and second positions; a drive beam configured for translation through the cartridge assembly to eject the plurality of surgical fasteners from the cartridge assembly; a pawl assembly coupling the drive beam to the rack such that the drive beam is incrementally advanced along the rack and through the cartridge assembly as the distal piston member oscillates between the proximal position and the distal position; and a retraction assembly coupled to the drive beam and the pawl assembly, the retraction assembly selectively actuatable for translating the drive beam proximally through the cartridge assembly, the retraction assembly including a retraction cord coupled to the drive beam and the pawl assembly at a first end thereof and having a retraction knob disposed at a second end thereof.