A case of superior mesenteric artery syndrome is reported. A 16-year-old boy with bilious vomiting for six months and weight loss within the previous year is presented. In this symptomatic period, he was fed many dietary formulations. This conservative management failed. Physical examination revealed that he was malnourished. The diagnosis was made by means of an upper gastrointestinal barium study performed through a tube. Gastrojejunostomy was preferred over duodenal mobilization because he had a markedly dilated stomach and enlarged pylorus. The postoperative course was satisfactory.