In young patients with advanced necrosis of the femoral head, the short- and medium-term results of total prosthesis arthroplasty are the most satisfactory. However, the prospect of aseptic loosening hangs over such arthroplasties like Damocles' sword. Reports from the literature suggest that, in addition to the age of the patient, there is also an endogenous factor that can be responsible not only for the etiology and pathogenesis of the necrosis, but also for the early loosening of the prosthesis. We have followed up 54 patients (73 hip joints) who had total hip replacement as a result of necrosis of the femoral head between 1976 and 1988. Altogether, 3 acetabular and 5 femoral shafts had to be replaced (7 patients). This corresponds to a loosening rate of 10% after an average of 4.9 years. Hence, the prosthesis changing rate is lower than that reported by other authors, but is still higher than in patients with coxarthrosis. Only 2 of 52 cemented shaft prostheses had to be replaced; the average age of these patients was 61.4 years. Of the 21 cement-free shaft implantations, 3 had to be replaced, the average age of these patients being 42.9 years. The fact that the average age of the latter patients was lower may be the reason for the revision rate not being significantly higher for the non-cemented shafts. In view of the fact that necrosis of the femoral head can rapidly result in the patient becoming an invalid if it is allowed to follow its natural course, hip joint prostheses should also be offered to younger patients.