BACKGROUND Traditionally, the common bile duct (CBD) is closed with T-tube drainage after choledochotomy and removal of CBD stones. However, the insertion of a T-tube is not without complication and the patients have to carry it for several weeks before removal. In the laparoscopic era, surgery is performed with minimally invasive techniques in order to reduce the trauma, hasten recovery, and reduce the hospital stay of patients. T-tube insertion seems to negate these benefits. This randomized study was designed to compare the two methods applied after LCBDE and to determine whether primary closure can be as safe as closure with T-tube drainage. METHODS From May 2000 to January 2008, 93 consecutive patients with common bile duct stones (CBDS) and gallbladder in situ were enrolled in this randomized study to undergo laparoscopic cholecystectomy with laparoscopic common bile duct exploration (LCBDE). Intraoperative findings, postoperative complications, postoperative stay, and hospital expenses were recorded and analyzed. RESULTS There was no mortality in both groups. A T-tube was inserted in 46 patients and the CBD was closed primarily in 47. There were no differences in the demographic characteristics or clinical presentations between the two groups. Compared with the T-tube group, the operative time and postoperative stay were significantly shorter, the hospital expenses were significantly lower, and the incidences of overall postoperative complications and biliary complications were statistically and insignificantly lower in the primary closure group. CONCLUSIONS LCBDE with primary closure without external drainage after laparoscopic choledochotomy is feasible and as safe as T-tube insertion.