As the oncologic safety of coloanal anastomosis (CAA) has been proved by many other authors, the incidence of CAA following ultralow anterior resection has increased. The purpose of this study is to evaluate the functional outcome and complications of patients who underwent ultralow anterior resection and CAA for distal rectal cancer. Fifty-seven patients underwent CAA following ultralow anterior resection between July 1997 and November 2003. Forty-four patients, who were followed up more than 6 months after diverting ileostomy closure, were evaluated for recurrence, complications, and functional outcomes. The mean follow-up period was 36.3 +/- 22.8 months (range, 8-83 months). The complications were multiple fistula (n = 3), fistula with anal stenosis (n=1), local recurrence with anal stenosis (n = 1), and anal stenosis (n = 7). Anal incontinence (Kirwan grade III) was noted in 14 patients, and bowel movements were observed more than six times per day in 16 patients. Overall recurrence occurred in six patients (13.6%). The 5-year survival rate was 85.3%, and the disease-free 5-year survival rate was 73.3%. Although CAA in patients with rectal cancer provides excellent long-term survival, a low risk of recurrence, and tolerable function, complications and poor functional outcomes of CAA do occur. Therefore, the choice of this method should be considered carefully.