A report was made of 35 Charnley prostheses implanted between 1962 and 1965. The occurring complications were discussed. In an exceptionally high number of these complications, fracture of the acetabulum proved to be the most important factor. Causes and predisposing factors were presented. Finally, reference was made to the significance of some of the experiences acquired on the basis of the long-term results which were published in this form for the first time.