The aim of this study was to evaluate whether stapler size used at ileal pouch–anal anastomosis (IPAA) influences outcomes.Data of patients undergoing stapled IPAA (1983–2007) were obtained. Differences between groups A (stapler size 28–29 mm) and B (31–33 mm) for pre- and perioperative factors, stricture, leak, quality of life (QOL), and function were compared. Associations between stapler size and stricture or leak were assessed with a multivariable Cox model.Groups A (n = 1,221) and B (n = 899) had comparable age, diagnosis, body mass index (BMI), and albumin level. Group B had more males (P < .001) but fewer patients with ileostomy (P < .001). There was no significant difference in rates of leak (4.5% vs 6.2%, P = .08) or stricture (1.9% vs 2.7%, P = .1) for groups A and B. On multivariate analysis, female gender was associated with stricture, while greater BMI and male gender were associated with leak. Group A had greater urgency at 1 year and nighttime pad use at 15 years. The other determinants of function and QOL were similar.There was no significant association between the size of stapler used at IPAA and long-term complications.