We had replaced 159 hips in 130 patients with cementless porous-coated AML porsthesis at Kwang Ju Christian Hospital between April 1987 and Feb. 1992. Among them, 100 cases(80 patients) could be analyzed clinically and radiologically with an average follow-up of 38.5 months(range 10 months to 74 months). The purpose of this study was to evaluate the relationships of initial fit, follow up stability and clinical results. The results were as follows. 1. The average postoperative Harris hip score was 90 points(preop. 42) at the follow-up of 1 year or more, the pain score 41 points(preop. 15). 2. When the surgical fit of stem was achieved properly, fixation by bone ingrowth could be expected. Simultaneously adequate fit of acetabular cup provided stable fixation. 3. The incidence of thigh pain was high in patients with an unstable implant of stem and the hip pain was more common in group of a definitely unstable cup. 4. Stress shielding was seen in 44 cases(44%). Of the 44 cases, 38 cases(86%) revealed in bone ingrowth. In conclusion, this study showed good clinical result of THR using AML prosthesis at the average follow-up of 38.5 months and it seemed to be influenced by initial fit significantly. But long-term follow-up is needed for accurate clinical and radiological evaluation.