Computerized tomography has been used in the evaluation of the intracranial lesions. Recently the usage of computerized tomography has progressively widened in many fields of clinical practice. In orthopedics computerized tomography has been tried in the diagnosis and the determination of treatment of tumors, spinal disorders, hip disorders and knee problem. Four problem cases in which concentric reduction could not be obtained after closed reduction of hip dislocations were evaluated by computerized tomography from Apr, 1, 1983 to Mar. 31, 1984 in the Capital Armed Forces General Hospital and following conclusiions were obtained: 1. Open reduction revealed that muscles(adductor and pyriformis muscles), joint capsule and osteocartilaginous loose bodies (femoral and acetabular) were interposed to hinder concentric reduction. Large posterior acetabular fragment induced instability and redislocation of the hip. 2. When there were 2-3 mm lack of symmetry of the two femoral heads or any abnormal findings(breakage of Shenton's line etc.) in plain roentgenography, computerized tomography was recommanded, and muscles, osteocartilaginous loose bodies and instability were found. 3. Computerized tomography is an easy simple method and has a great diagnostic value in the evaluation of asymmetry and instability after closed reduction of traumatic hip dislocations.