Abstract: A reciprocating saw attachment for a chain saw whereby the rotating chain saw drive converts the attachment to reciprocating movement to operate a saw blade longitudinally remote from the chain saw tool. It comprises a guide bar having one end formed to replace the prior art guide bar. The guide bar of this invention is formed with a slotted aperture in the body thereof and carries a sprocket wheel at the distal end of the guide bar. An endless link chain encircles the edge of the guide bar, the sprocket drive of the chain saw motor and the sprocket wheel mounted on the guide bar. A slide block is reciprocally movable in the slotted aperture and driven by a crank lever connecting the sprocket wheel and the slide block. A longitudinal pole is mounted on the guide bar for distally supporting an elongated push rod mounted on the guide bar for reciprocal movement. The proximate end of the elongated push rod is linked to the slide block.