The presence of endometrial tissue in airways, pleura and lung parenchyma is called thoracic endometriosis syndrome (TES). It is a rare pathology, and typically consists of catamenial pneumothorax, haemothorax, haemoptysis, and pulmonary nodules. We report a case of a 36-year-old woman with thoracic endometriosis causing catamenial haemothorax.The diagnosis of thoracic endometriosis is complicated and often delayed. TES should be suspected in a reproductive age woman with exacerbating symptoms during the menstruation. Treatment may be medical and surgical.