During a 14-year period ending in June 1979, 342 patients with calculous biliary disease underwent choledochoduodenostomy either as a primary procedure or during reoperation. Eighty per cent of the patients were aged 50 years or more. Follow-up was either by personal interview and physical examination or by means of a questionnaire, 90 per cent of the patients being assessed at periods ranging from 6 months to 14 years. A high incidence of common bile duct dilatation was found in older patients, in patients with a long history and in patients submitted to reoperation. There were no operative deaths. Postoperative complications occurred in 22 cases (6.4 per cent) and, in particular, no patient developed ascending cholangitis or symptoms related to the "blind segment". Choledochoduodenostomy is a valuable and safe procedure and can be used on wide indications, especially where peroperative cholangiography is not available.