PURPOSE: The aim of this study was to analyze the risk factors of pouch failure after a restorative proctocolectomy. METHODS: A restorative proctocolectomy was performed in 169 patients between November 1989 and May 2007. A retrospective review was done for postoperative complications and follow-up results of pouch failure, and the risk factors of pouch failure were analyzed. Pouch failure was defined as having occurred when a permanent ileostomy was constructed, regardless of pouch removal. The median follow-up was 48 (3~155) months. RESULTS: Among the 169 cases, 86 cases involved ulcerative colitis (UC group), 70 cases involved familial adenomatous polyposis or attenuated adenomatous polyposis coli (FAP group), and the remaining 13 involved hereditary nonpolyposis colorectal cancer or synchronous colon and rectal caner (CRC group). The sex ratios and the incidences of comorbidity were not significantly different between the groups, but the mean ages were. Complications occurred in 61 patients (36.1%): pelvic sepsis (28 cases), pouchitis (23 cases), desmoid tumor (12 cases), wound infection (10 cases), and anastomosis stricture (4 cases). The 5-year cumulative rate of pouch failure was 9.8%. Presence of a desmoid tumor, pelvic sepsis, and anastomosis stricture were risk factors of pouch failure. CONCLUSIONS: The cumulative pouch failure rate after a restorative proctocolectomy was 9.8% for 5 years, and pouch failure was associated with the presence of a desmoid tumor, pelvic sepsis, and anastomosis stricture.