The unusual intraoperative complication of inadvertent formation of a stapled colovaginal anastomosis is described in a 61-year-old woman with diverticular disease. Intraoperative complications of linear staplers, linear cutters and circular end-to-end anastomotic staplers are reviewed, as are methods of prevention and management of such complications. The discussion focuses mainly on the complications that may arise in low anterior resection. They are more likely due to operator error than to instrument failure.