In the present case, the subject was a 31-year-old woman with obesophobia who restricted her energy intake and repeatedly induced vomiting and misused laxatives after binge eating, which caused a sudden weight loss of 29 kg in approximately 5 months. In January 20XX, the subject was first examined as an outpatient at our psychiatric department at the recommendation of her eldest son. Upon diagnosis of anorexia nervosa, the subject underwent outpatient treatment ; however, there was no improvement in the disturbance in self-per- ceived weight or shape, and the subject voiced her desire to lose weight. In May 20XX, the subject complained of chest pain, pharyngeal pain, and respiratory distress after self-induced vomiting and was, thus, examined at the psychiatric outpatient services. Chest X-ray and chest CT revealed pneumomediastinum and subcutaneous emphysema. Spontaneous oesophageal rupture, a fatal condition, was suspected and, therefore, the subject was transferred to a more advanced medical institution capable of esophageal surgery. After admission, spontane- ous oesophageal rupture was ruled out based on the results of upper gastrointestinal endos- copy with esophagography, and spontaneous pneumomediastinum was diagnosed. The pneu- momediastinum disappeared with conservative treatment ; however, after approximately 8 months, spontaneous pneumomediastinum recurred, following self-induced vomiting. For patients with eating disorders and who are involved in self-induce vomiting, we believe that the vomiting can cause pneumomediastinum, and it is assumed that continuation or recommencement of vomiting can potentially increase the risk that pneumomediastinum will recur. We, therefore, report recurring pneumoediastinum as a physical complication caused by self- induced vomiting that should be noted in clinical practice of the psychiatric department.