OBJECTIVE: To analyse the risk factors for reoperation after initial surgical repair of congenital duodenal obstruction and demonstrate that they can be decreased with more careful attention and more advanced techniques during surgery. METHODS: The records of newborns and infants (aged 0-2 months) who had surgical therapy for congenital duodenal obstruction in the past 30 years were reviewed and analysed. Of the 298 patients, 132 (44%) were boys and 166 (56%) were girls. All patients who underwent repeat surgery postoperatively were evaluated by the reasons for surgery. The number of patients with various combination lesions of congenital duodenal obstruction was also calculated and the relationship to postoperative reoperation was analysed. RESULTS: Twenty patients (6.7%) had congenital duodenal obstruction with combination lesions including duodenal web, malrotation, annular pancreas and multiple duodenal web. Twelve patients required further operation 5 days to 2 years postoperatively for complications (n = 5) and other duodenal atresias that were not discovered initially (n = 7). CONCLUSION: More than half of reoperated patients (7/12) had multiple lesions of duodenal obstruction that were missed during the primary operation. The postoperative reoperation rate for congenital duodenal obstruction could be decreased with more careful attention to operative details and more preoperative and intraoperative evaluation of the gastrointestinal tract. © 2005 Elsevier. All rights reserved.