Situs inversus (SI) complicating neonatal bowel obstruction presents a challenging complex, and to facilitate rational decision making for treatment, we have reviewed 23 cases of abdominal SI seen in our hospital over the last 25 years. Preoperative roentgenographic studies most always predicted SI, the specific patient groups including: 12 abdominal SI with dextrocardia, 10 abdominal SI with levocardia, and 1 with partial heterotaxia. Major intraabdominal anomalies produced surgical emergencies in 7 neonates in the first year, 6 of these 7 being in the first month of life. In these 7 patients, multiple anomalies occurred including 1 child with a rotational anomaly with reversible ischemia secondary to midgut volvulus, and 4 with a rotational anomaly without volvulus, all being treated with a modified Ladd procedure. One of these children had an unrecognized intraluminal duodenal membrane, 1 an operatively diagnosed intraluminal membrane, 1 had annular pancreas, and 1 had a discontinuous jejunal atresia. A preduodenal portal vein was present in 4 of the 7 children, a branch being divided in 1 and the full vein bypassed in 2 of the other 3 patients. Two patients had biliary atresia, one of whom also had a diaphragmatic hernia. Five of the 7 neonates had associated major congenial heart disease accounting for 2 of the 3 deaths in this series. This review emphasizes the protean nature of abdominal SI, especially as it may cause or contribute to neonatal intestinal obstruction; and it is this understanding which is a prerequisite to optimal operative management.