Of 165 renal Transplantated patients, 12 developed aseptic bone necrosis in the femoral head (6 patients), in the femoral condyle (5 patients), in the astragalus (1 patient). The onset of symptoms was 6 to 23 months after transplantation. 99mTc-O4-MDP bone scintigraphy and radiological examination associated with clinical signs confirmed the diagnosis. Unresolved hyperparathyroidism, phosforus depletion, ponderal increase, total i.v. prednisolone-boluses and trauma represented conditions which might predispose to the development of lesion. 8 patients were managed with conservative treatment. 4 patients required a total of 8 operations: head replacement arthroplasty and articular cartilage reimplant in two patients with disease involving femoral head; articular cartilage reimplant and condyle replacement arthroplasty in two patients with disease involving femoral condyle.