The degree of anatomical revascularization of a necrotic femoral head and traumatic hip would provide information about treatment and prognosis. The authors analyzed the vascular changes of femoral head among unilateral avascular necrosis, bilateral avascular necrosis, and traumatic hips. Forty-four patients with avascular necrosis and 19 patients with traumatic hips were examined by selective angiography of the medial femoral circumflex artery. In the traumatic hip cases, 12(63%) showed occlusion, 2(11%) hypertrophy of the capsular branches, and 5(26%) were normal. In the avascular necrosis cases, 15(25%) showed occlusion, 39(67%) had hypertrophy of the capsular branches, and 4(7%) had normal findings. Hypertrophy of the superior capsular branch of the medial femoral circumflex artery is more frequently observed in avascular necrosis than in traumatic hip. Bilateral avascular necrosis reveals more frequent incidences than unilateral cases. Selective angiography could help in the therapy plan and also provide informations about the contralateral side.