Fourty-two patients with superior mesenteric artery syndrome were treated surgically. Among the patients, 24 were male and 18 female (mean age, 38 years). The courses of the disease varied from 1 to 10 years. Operations included amputation of the ligament of Treitz (14 patients), gastrojejunostomy (2), subtotal gastrectomy and gastro jejunostomy (1), duodenojejunostomy (6), anterior repositioning of the duodenum (7), and circular drainage operation of the duodenum (12). Two patients underwent anterior repositioning of the duodenum and gastrojejunostomy. In patients without relief of symptoms such as vomiting after operation, circular drainage of the duodenum was performed. All the 42 patients were successfully treated. The authors discussed 6 kinds of operations, their indications, and the advantages and disadvantages. Emphasis was given to the anterior repositioning of the duodenum and its circular drainage.