Abstract Four patients under 45 years old presented with small bowel infarction secondary to superior mesenteric venous thrombosis. Diagnosis was not made pre-operatively in three patients and delay to operation of over 4 days occurred in two patients. In each case infarcted bowel was resected and a primary anastomosis fashioned. A further resection of infarcted small bowel was necessary in three patients. Each patient was discharged on long-term warfarin therapy. Two patients required permanent total parenteral nutrition, one of whom died of liver failure at one year. The remaining patients remain well.