Hip fusion has provided disease eradication, stabilization, pain relief and strenuous activity, but the possible complication of pseudarthrosis as well as loss of all motion is a drawback. Total hip replacement arthroplasty has not been a good procedure for active young patients. This study was perforrned to clarify the indications, the best position, the functional results of hip fusion and the effect of hip fusion on the adjacent joint. The authors reviewed 32 cases of hip fusion performed at the Department of Orthopedic Sugery, Seoul National University Hospital during the period of 11 years from April 1973 to June 1984 and the following results were obtained. 1. The average age of the patients at the time of operation was 20.3 years. 2. Tuberculosis of the hip was the most common cause (56.2%). 3. The satisfactory fusion was obtained in 26 cases (81,2 %). 4. The average position of fusion was 20±9 degrees of flexion, 1±5 degrees of abduction and 10±4 degrees of external rotation. 5. Although there was a disability due to limitation of motion after hip fusion, leg length discrepancy was reduced from 3cm (preoperative) to 2.5cm (postoperative) and scoliosis was decreased from 18' of Cobbs angle (preoperative) to 12' of Cobbs angle (postoperative). 6. After hip fusion, walking capacity was increased and back pain was reduced. 7. Age was barely correlated with absolute clinical scores, but better functional results were obtained in younger patients than in older patients. 8. The results were excellent or good in 24 cases (75%).