Acute onset dyspnea in a patient with history of blunt chest injury can be due to traumatic hemothorax. The most common cause of hemorrhagic pleural effusion is trauma. Apart from trauma, malignancy and pulmonary embolism are the other major causes of hemorrhagic pleural effusion.1 Herein we present a case of dissecting aneurysm of descending thoracic aorta presenting initially with shortness of breath due to right sided massive pleural effusion.