We report two identical male twins who suffered from superior mesenteric artery (SMA) syndrome. A 28-year-old man was admitted for investigation of postprandial nausea and vomiting. Upper gastrointestinal examination revealed a dilated proximal duodenum with an abrupt vertical cutoff of barium flow in the third portion of the duodenum, establishing the diagnosis of SMA syndrome. One year later, his twin brother also presented similar symptoms and was radiologically diagnosed as SMA syndrome. The twin brothers did not respond adequately to conservative therapy and underwent duodenojejunostomy. This is the first report of SMA syndrome in identical twins.