Endometriosis is a chronic inflammatory gynecologic disease. Problems associated with endometriosis include dysmenorrhea, dyspareunia, and infertility. We managed two patients between March 2001 and December 2011 with extrauterine endometriosis. The first was a 37-year-old unmarried woman who was admitted for recurrent pneumothorax that was consistent with her menstrual cycle. She had received a gonadotropin-releasing hormone (GnRH) analogue injection and tibolone to prevent menopausal symptoms such as hot flashes for the past 2 years and had no recurrent pneumothorax. A 22-year-old woman arrived at the hospital with hemoptysis during menstruation, which had been occurring for the past 5 months, and chronic iron deficiency anemia. After one GnRH analogue injection per month, the hemoptysis and anemia resolved. Catamenial pneumothorax is a rare occurrence with ectopic endometriosis. Diagnosis and management are extremely crucial and difficult for the gynecologist. Our data provide an aid for managing patients with catamenial pneumothorax.