The authors studied 126 cases (90 patients) of proven avascuar necrosis of femoral head inadult during theperiod from Jan. 1975 to May 1982 at Kyung Hee University Hospital. The results were as follows; 1. The sex ratiowas 63 males to 27 females and the peak incidence of age was in the fifth decade. 2.Among the 90 patients, thecause and conditions associated with avascular necrosis were idiopathic in 33 cases, femoral neck fracture in 32cases, chronic alcholism in 9 cases, anti-inflammatory drugs abuse in 6 cases, corticosteroid therapy in 5 cases,caisson's disease in 2 cases, hip dislocation in 2 cases and macromolecular storage disease in 1 case, in theorder of frequency. 3. Excluding 34 patients of avascular necrosis associaited with trauma, bilateral lesion was36 patients(64.3%) among the 56 patients. 4. The radiographic features in femoral head were variable, such as 118cases of central increased density surrounded by lucent zone, encompassed by dense rim, 110 cases of collapsedarticular cortex and 16 cases of intact articular cortex, 91 cases of flattening of femoral head, 79 cases ofcrescent sign, 51 cases of fragmentation of osteonecrotic segment, 47 cases of superimposed degenerativearthritis, 5 cases of patchy increased density, and 3 cases of no radiographic change. 5. The bone scintigraphywith Tc-99m-MDP was performed in 11 patients (15 cases) and its finding in femoral head were 8 cases of increasedradioactivity, 4 cases of mixed increased and decreased radioactivity, and 3 cases of absent radioactivity. 6. Itwas our belief that comparative study of plain radiographs and bone scintigraphy would be useful in earlydiagnosis and tratment planning of avascular necrosis of femoral head.