Superior mesenteric artery syndrome (SMAS) is an uncommon cause of vomiting and weight loss due to compression of the third part of the duodenum by the superior mesenteric artery. Small bowel adenocarcinoma is an uncommon tumor, which is frequently delayed in diagnosis as its symptoms and signs are non-specific. The present study describes a case of SMAS occurring in a 51-year-old man, caused by intestinal obstruction secondary to a primary adenocarcinoma of the duodenal-jejunal junction. To the best of our knowledge, the present case is the first report of small bowel adenocarcinoma masquerading as SMAS. The present case highlights the importance of considering the possibility of SMAS in patients with upper bowel obstruction caused by intestinal carcinoma.