Clinical and radiological studies were performed on forty total hip replacements (THR) (38 patients) using bone graft acetabuloplasty. Using the Japanese Orthopaedic Association hip score, the mean preoperative total score improved from 41.3 to 84.6 points 1 year postoperatively, and slightly decreased to 84.1 point by the mean follow-up period of 4 years and 5 months. By radiological evaluation, the setting angle of the socket was an almost ideal angle (41.5°) and the mean Sharp angle was 44.5°C pre-operatively and 33.3° post-operatively. The lesser trochanter was lowered to the normal position, and therefore leg length was corrected to almost equal. The size of the grafted bone was about 1/32/3 of the femoral head of the other side, and the resected femoral head was suitable for grafted bone. The grafted bone was united about 3 months after the operation. Prosthetic loosening reached stage II in the socket side by Uno's classification, but on the stem side, Müller type showed an increased rate. Bone graft acetabuloplasty was an useful method to set the socket at the ideal position in THR of dysplastic hips.