A 35-yr-old woman, with profound dyspnea at rest and failure to thrive, asked to be evaluated at Stanford Medical Center. She requested a second opinion after entering death counseling in another institution because of an unrelenting, deteriorating course caused by pulmonary lymphangiomyomatosis. Her recurring right chylous pleural effusion was drained by chest tube, a LaVeen shunt was placed to decompress her severe chylous ascites, an oophorectomy was performed, large dose progesterone (medroxyprogesterone acetate) was initiated intramuscularly, and during her hospitalization she was fed by total parenteral nutrition. She was discharged mildly improved after 2 months. Now, 3 yr later, her pulmonary function tests and chest radiographs are improved, and she walks 2 miles per day and teaches school full time. Extensive hormonal analysis did not reveal an endocrinologic abnormality that could explain the pathophysiology of her disease. However, the patient had multiple human chorionic gonadotropin injections before becoming ill, as have a number of other patients who have developed this disease. This report is an example of successful treatment of severe pulmonary lymphangiomyomatosis.