Out of a total of 183 patients with displaced intracapsular fractures of the femoral neck, 40 were treated with percutaneous cannulated screw fixation according to the 'three point principle'. These patients were reviewed retrospectively, paying special attention to mechanical failure. Thirty-five fractures healed in a good position. Four fractures (10 per cent) showed signs of recurrent instability, resulting in non-union in two and malunion in one. In all four cases of mechanical failure faults in the operative technique or indication could be established. We conclude that percutaneous cannulated screw fixation is a promising method. However, the right indication and a precise operating technique are important.