OBJECTIVE Although a temporary diverting stoma is a frequent surgical procedure for the protection of anastomosis in a sphincter-preserving operation for lower rectal cancer, its impact on anastomotic leakage is not conclusive. This study was designed to evaluate anastomotic complications after ultralow anterior resection and handsewn coloanal anastomosis without a diverting stoma for lower rectal cancer patients. METHODS Between January 1995 and December 2005, 96 patients were treated by ultralow anterior resection and handsewn coloanal anastomosis for lower rectal cancer. Fifty-one patients received preoperative concurrent chemoradiation, whereas 45 had no preoperative treatment. No diverting stoma was created in any of these cases. The anastomotic complications were evaluated between the groups. RESULTS Six of 96 patients (6.1 percent) developed anastomotic complications: three anastomotic stenoses, one partial anastomotic dehiscence, one retrorectal abscess, and one rectovaginal fistula. All of the complications occurred in the preoperative radiation group, whereas none from the nonradiation group had an anastomotic complication (P=0.017). The patients with stenosis and partial dehiscence were managed conservatively. The patient with retrorectal abscess was treated with debridement, irrigation and drainage, and seton procedure with a transanal approach. The patient with rectovaginal fistula underwent a second coloanal anastomosis. CONCLUSIONS The anastomotic complication rate was low even without a diverting stoma. This study suggests that a diverting stoma is not necessary when performing a handsewn coloanal anastomosis for lower rectal cancer however, an effort should be made for healthy anastomotic healing in patients with rectal cancer who are preoperatively radiated.