Rupture or laceration of the aorta is a more common result of nonpenetrating traumatic injury than is generally appreciated. If the lesion is promptly diagnosed, a appropriate surgical treatment may be life-saving. Diagnosis may be difficult and at times the rupture may remain clinically silent for variable period.< A 34 - year old male patient had sustained steering wheel injury to his chest during automobile accident 8 weeks prior to admission. The diagnosis of traumatic aneurysm of the aorta was delayed as he was asymptomatic. Surgical repair of false aneurysm of the descending aorta was successfully performed by partial cardiopulmonary bypass through the femoral artery and vein.