Purpose: We hereby would like to compare on the basis of the initial 12 hips and latter 18 hips by analyzing the initial results of the minimal incision total hip arthroplasty of 30 hips we experienced. Materials and Methods: For the period of December 2004 through June 2005, we performed the total hip arthroplasty with minimal incision in 10cm or shorter using the posterolateral approach on 25 patients (30 hips) whose BMI(body mass index) is 30 or lower. We compared by analyzing results of the initial 12 cases and 18 latter cases. Results: The average BMI was 23.7. There weren`t statistically meaningful differences the change in the hemoglobin value of pre-op and post-op, necessity of blood transfusion, position of component, and the Harris hip score 6 weeks after operation. But, the average initial operation time of 124 minutes was remarkably reduced to 65 minutes in average in the latter operation and the length of a skin incision was reduced from the average 9.2 cm in the initial operation to an average of 8.1cm in the latter operation. There wasn't the malposition of acetabular cup and femoral stem. Conclusion: Although we need more statistical data through more cases and the analysis of long-term results, we think that, to surgeons with much experience in the conventional total hip arthroplasty, the total hip anthroplasty using minimal incision for patients with BMI of 30 or below would be a useful approach having the advantage in a cosmetic aspect.