This is a case report of a 51-year-old woman with bilateral stress fractures of the pelvic rami and a history of anorexia nervosa (AN). AN is a psychiatric condition of low weight caused by restricted food intake, impaired body image and an exaggerated fear of gaining weight in addition to compensating behaviour such as excessive physical activity. Among patients with AN, reduced bone density is common, and a higher risk of fractures is present. Stress fractures should be suspected in patients, who have AN and experience pain from the musculoskeletal system without a history of trauma.