Abdominal situs inversus carries a significant mortality because the majority of cases (95 %) have associated cardiac and splenic defects (9). A review of all cases reported in the English literature confirms in addition the presence of significant gastro-intestinal pathologies, mainly annular pancreas, midgut volvulus and duodenal atresia. We report on an additional case of abdominal situs inversus without cardiac or splenic abnormalities, who had partial duodenal obstruction secondary to a mucosal diaphragm. This seems to be the thirteenth case associated with duodenal obstruction and the sixth case secondary to a mucosal duodenal diaphragm, to date, in this setting (1, 2, 3, 4, 5, 7).