Summary On the basis of the results obtained in 712 patients, an evaluation of the effectiveness of transduodenal sphincteroplasty is presented. This procedure has proved to be appropriate in treating benign obstruction of the common bile duct as well as choledocholithiasis. Mortality was 1.1 per cent and long-term results were satisfactory in 97 per cent of the cases. Only sixteen patients required reoperation for residual or recurrent stones or for stricture of the sphincter of Oddi. Compared with choledochoduodenostomy, sphincteroplasty avoids the hazards of the so-called sump syndrome and of ascending cholangitis by reflux of intestinal contents into the common duct. A high incidence of postoperative pancreatitis in patients who undergo sphincteroplasty has not been observed.