The authors report on a consecutive series of 123 children (46 males, 54 females) with congenital duodenal obstruction who were operated on between 1962 and 1980 at the Department of Paediatric Surgery, University of Heidelberg, Surgical Centre. 78 patients (64%) had an extrinsic obstruction; in 36% of the children a membraneous stenosis or complete atresia was observed. 74 children (60%) were mature at birth and had no additional malformations. Out of the remaining 49 children, 25 were mature but had additional malformations. 13 prematurely born children without and 11 prematurely born children with additional malformations were seen. 17 (14%) out of 123 children died. In 74 cases with uncomplicated duodenal obstruction only 5 children (5%) died, as compared to 13 children (27%) out of 49 cases with complicated obstruction. A division of our patients into two time spans (1962 to 1971, 1972 to 1980) shows a total lethality of 25% for the first series, which included 39% cases with complications. In a consecutive series of 54 children operated between 1972 and 1980 no child died.