Clinical observation was performed on the 84 hips of 72 patients which were replaced by total hip, who were treated at Department of Orthopedic Surgery, College of Medicine, Busan National University, from March 1978 to March 1981. The follow-up period of each case varied from 1 to 4 years. The results obtained were as follows: 1. The peak age incidence ranged from 51 to 60 years, which comprised 37.1% (23 patients) of total cases. 2. The causes of the hip diseases were; 25 cases of post-traumatic avscular necrosis of the head, which comprised highest incidence, 19 osteoarthritis, 14 primary avscular necrosis of the head, 4 ankylosing spondylitis, and 3 rheumatoirl arthritis. 3. The most commonly used prosthesis was Muller type in 64 cases (88.9%); Trapezoidal-28 in 3 cases; Ceramic-metal type in 4 cases; and modified Muller type by Japanese in 1 case. 4. Anterolateral approach was used in all cases except for the 3 cases in whom anterior approach was made. In most cases, greater trochanter osteotomy was not performed except for the 9 cases in whom operative field were poorly exposed without osteotomy. 5. Several complications developed; perforation of femur shaft and acetabulum during the operation in 1 case each, Post-operative deep seated infection in 2 cases, thrombophlebitis in 1 case, wire breakage in 2 cases, stem failure in 1 case, and femoral shaft fracture in 1 case. 6. Postoperative functional evaluation by the Merle d'Aubigne and Postel method was done; pain relief in 92.4%, mobility recovery in 71.6% and functional inprovement in 70.1% belonged to grade 5 and 6. Relief of pain is the most prominent effect of the total hip rep1acement surgery in this series.