The clinical entity in which functional endometrial tissue is present in the thoracic cavity causing various clinical manifestations is called thoracic endometriosis syndrome (TES). Catamenial hemothorax (CHt) is a clinical manifestation of TES characterized by recurrent hemothorax which occurs during each menstrual cycle. The establishment of a correlation between menstrual cycle and clinical features is necessary for the diagnosis. We report a case of CHt in a 36-year-old female who presented with recurrent right-side pleural effusion.