A follow-up is given of early and late results in 109 arthroplasties with the self-locking Austin T. Moore vitallium femoral head prosthesis in fractures of the femoral neck on 106 patients. Operative indication was usually fresh medical fracture of the femoral neck in an elderly woman, or its late complication. The surgery was performed in a unit for general surgery also engaged in pre- and postgraduate teaching activities. Many operations were performed by residents engaged in general surgery or orthopaedics. Point scores according to a modification of Merle D'Aubigné's classification showed excellent or at least good results in 81 per cent of the 69 mobile patients. Because of deteriorated general physical condition 11 patients were chronically bed-ridden. Five patients could not be reached. In three instances the prosthesis was removed. 21 patients died, three during the stay in hospital and 18 later for reasons not connected with the operative procedure. The mortality during 40 months of observation corresponded fairly well to that expected in the age group for the population as a whole.