Thoracic endometriosis is an uncommon disease that has four main forms: catamenial pneumothorax, hemothorax, hemoptysis, and pulmonary nodules. Since the growth of endometrial tissue depends on the presence of estrogen, thoracic endometriosis usually occurs in menstruating women between 25 and 35 years of age. Menstrual disturbances are common in women with chronic kidney disease (CKD). However, they could be reversed after kidney transplantation. Therefore, previously asymptomatic endometriosis may become symptomatic after kidney transplantation. A 49-year-old woman with CKD underwent kidney transplantation. A month later, she experienced dyspnea, and hemothorax in her right hemithorax. However, there was no evidence of infectious diseases and malignancy in thoracentesis, pleural biopsy, and computed chest tomography (CT). The serum and pleural fluid levels of his carbohydrate antigen 125 were elevated. Hemothorax secondary to pleural endometriosis was suspected. We tried hormonal therapy, and the hemothorax disappeared. At the sixth-month follow-up, there was no recurrence of hemothorax.