Thoracic endometriosis syndrome is the presence of endometrial tissue in or around the lung. Thoracic endometriosis syndrome consists of four distinct clinical entities: catamenial pneumothorax, catamenial hemothorax, hemoptysis, and pulmonary nodules. Thoracic endometriosis syndrome is a rare and complex condition, and diagnosis is often delayed or missed by clinicians, which can result in recurrent hospitalizations and other complications. Current treatments include hormone therapy and, where warranted, surgical intervention. We report the case of a 48-year-old woman with endometriosis causing bowel obstruction and concurrent catamenial pneumothorax.