Eating disorders are an important cause of physical and psychosocial disturbances. Gastrointestinal complications in eating disorders are common and include pancreatitis and superior mesenteric artery syndrome (SMAS). However, only two patients who simultaneously suffered from both SMAS and pancreatitis in the setting of an eating disorder have ever been reported in the literature. We describe here a patient with eating disorder not otherwise specified (ED-NOS) who exhibited both SMAS and pancreatitis concomitantly. An 11-year-old boy with ED-NOS had presented with the sudden onset of recurrent bilious vomiting, abdominal distension and abdominal pain. Laboratory and imaging studies revealed that the patient had SMAS and acute pancreatitis. Gastric decompression and intravenous infusion of fluids promptly improved his abdominal symptoms and laboratory data. This is the first case report of a patient with ED-NOS who simultaneously suffered from SMAS and pancreatitis in the pediatric literature. Since SMAS and pancreatitis can both cause patients to be severely ill, these diseases should be considered in patients with eating disorders who exhibit abdominal symptoms such as vomiting or abdominal pain.