In this report, we described a case of jejunum cancer that presented with abdominal pain and vomiting as chief complaints, which mimicked superior mesenteric artery syndrome. An elderly woman in her 70s was referred to our department for prolonged abdominal discomfort. Findings from CT and abdominal echo indicated that superior mesenteric artery syndrome may be responsible for jejunum cancer. Upper gastrointestinal endoscopy revealed a peripheral type 2 lesion in the upper jejunum. Upon biopsy, the patient was diagnosed with adenocarcinoma(papillary type). Surgical resection of the small intestine was performed. Although small intestinal cancer is a fairly rare disease, it should be considered a differential diagnosis. Comprehensive evaluations including medical history and imaging should be considered.