Anorexia nervosa and psychogen vomiting are psychiatric eating disorders characterized by unexplained weight loss and induced vomiting. These diagnoses require absence of somatic disease. Achalasia is a primary disorder of the esophagus that can be responsible for the same symptoms. This may occult the real diagnosis, especially as dysphagia is not constant and variable in time. We report four cases of achalasia mistakenly diagnosed and treated as anorexia nervosa or psychogen vomiting. Achalasia was unrecognized because specific symptoms, such as dysphagia, were overlooked or misinterpreted by the patients' physicians and psychiatrists, or by the patients themselves. In patients with such eating disorders considered to be psychiatric, physicians should inquire about signs suggestive of achalasia. The diagnosis of achalasia is suspected by imaging and endoscopy, and confirmed or ruled out by manometry.