Abstract: Surgical instrument for aiming and hole-forming purposes for use for example in the implantation of locking nails or the like in bones, the instrument includes an elongated shank and having a gripping portion at one end thereof and an aiming portion at the other end thereof, the aiming portion including a guide member made of a material relatively transparent to X-rays, the guide member having a bore therethrough adapted to slidingly receive an elongated hole-forming tool and having aiming elements located in different planes, the guiding bore being dimensioned for the guidance of a wire-like piercing tool, and the aiming elements being located around the guiding bore in axially spaced planes such that images of the aiming elements coincide on an image screen when the axis of the guiding bore coincides with the beam direction of said X-rays.