A retrospective study was performed of forty-nine patients (fifty fractures of the femoral neck) who had Parkinson disease and who had had an endoprosthetic replacement of the femoral head. The average age of the patients was seventy-four years (range, forty-seven to ninety-two years). All of the fractures were Garden Stage III or IV. An anterolateral surgical approach was used in twenty-five hips; a posterior approach, in twenty hips; and a transtrochanteric approach, in five hips. An adductor tenotomy was required in five patients to release an adduction contracture. Ten patients died by the sixth postoperative month. The remaining thirty-nine patients were followed for a minimum of two years (average, 7.3 years). Common postoperative complications were infection of the urinary tract (20 per cent) and pneumonia (10 per cent). There was only one dislocation. At the time of writing, nineteen (80 per cent) of the surviving patients could walk.