46 patients with avascular necrosis of the femoral head were examined by T[sub 2]- and T[sub 1]-weighted MR before and after infusion of Gd-DTPA. Both sides were involved in 12 cases. The classification was done according to Ficat. In early stages and in postoperative studies a correlation of signal intensity after infusion of Gd-DTPA and clinical symptoms was found. Hyperintensity of the avascular area or of the implanted material was assumed to be vascularised or vital components in 4 cases of Ficat 1 and 15 postoperative studies. Contrariwise, we found in 5 patients with severe postoperative symptoms, low signal intensity areas due to avascular regions. (orig.).