This is a retrospective clinical analysis of the usefulness of loop ileostomy for the prevention of anastomotic leakage in patients with low rectal cancer when the low anterior resection or coloanal anastomosis is performed. We reviewed 54 cases of low rectal cancer from January 1994 to May 1996 at Department of Surgery, Wonju College of Medicine, Yonsei University. In 54 cases of low rectal cancer, 28 cases were ileostomy group and 17 cases were no stoma group. There were no differences in clinical characteristics such as age and sex distribution. Most patients were classified into stage B or C by modified Astler-Coiler classification but 2 cases of stage D that simultaneous liver resection was performed were in no stoma group. Tumor locations from the anal verge were 6.8 and 10.3 cm by mean in ileostomy and no stomp group, respectively(P<0.05). Heights of anastomosis were 3.7 and 6.8 cm by mean from the anal verge in ileostomy and no stoma group, respectively(P<0.05). Double stapling technique was used for anastomosis in most patients but hand-sewn technique was also carried out in 1 case in ileostomy group. The most common postoperative minor complication was wound infection in both groups. Anastomotic leakage rate was higher in no stoma group(4 of 17, 23.5%) than that of ileostomy group (1 of 28, 3.6%) but statistical comparison could not be confirmed(P=0.00). But interestingly, such complications as stoma perforation, stoma prolapse and parastomal hernia were developed in ileostomy group and that all complications should be corrected by ileostomy repair. As forementioned above, we had concluded that ileostomy could protect anastomosis site but above mentioned complications associated with building the stoma should be also prevented by careful surgical technique.