We have reported a case of hemoptysis caused by pulmonary parenchymal endometriosis which was apparently successfully treated with danazol. Bronchopulmonary endometriosis is a very unusual cause of hemoptysis, and should be suspected on the basis of cyclic hemoptysis with menstruation. Danazol is effective therapy, but information regarding optimal dosage and rates of recurrence after completion of therapy is limited at this time.