A method for computer assisted localization of the distal locking holes (11; 14) of an implanted intramedullary nail (2) having a nail axis (19) and a first and second distal locking hole (11; 14) by A) acquiring one single image IM of the distal end section (25) of said intramedullary nail by means of an X-ray device (9) whose optical axis (30) is oriented essentially perpendicular to the nail axis (19) but irrespective to the orientation of the distal locking holes (11; 14); and B) calculating the position of the first and second hole axis (23; 20) of the first and second distal locking hole (11; 14) with respect to a three-dimensional coordinate system A-COS (7) of the implanted intramedullary nail (2).