Résumé : A 1-year-old boy with high jejunal membranous stenosis was successfully treated “a minima” by antimesenteric longitudinal enterotomy over the diaphragm, excision of the latter, and transverse closure of the bowel. This was made possible by use of simultaneous peroperative endoscopy, which allowed exact localization of the diaphragm. Peroperative endoscopy is a useful and accurate method for this purpose and should be considered in similar cases. © 1993 Raven Press, Ltd., New York.