A retrospective study of 200 cases of subcapital fracture of the neck of the femur treated by sliding nail-plate fixation has been carried out. Failure of fixation within three months occurred in forty-two cases (21 per cent). These failures could, in part, be attributed to a combination of the severity of the fracture and various imperfections in technique. The age of the patient and the angle of the nail-plate had no significant effect on the result.