Twenty-nine patients undergoing primary closure (primary closure group) and seventy patients undergoing T tube drainage (T tube group) were compared clinically to elucidate the effectiveness and problems of the primary closure of the common bile duct for choledocholithiasis. The frequency of bile leakage after the operation was 24.1% in primary closure group. The frequency of localized peritonitis after removal of a T tube due to incomplete fistula formation was 8.6% in T tube group. Postoperative liver dysfunction was noted in 7.1% for primary closure group and in 14.3% for T tube group. The duration of hospital stay after the operation was 20.1 days in primary closure group, being significantly shorter than 38.8 days in T tube group. Recurrence of stones was observed in 1 patient for each group. Though the primary closure was predominantly performed for aged patients compared to T tube drainage group, primary closure group revealed less complications. In the primary closure group, shortening of duration of hospital stay after the operation and the same prognosis as that of T tube drainage group were obtained. We concluded that the primary closure of the common bile duct for choledocholithiasis is more effective than T tube drainage as long as the indications are kept.