We report the case of a patient admitted at the emergency unit after a severe car accident. As ECG showed a ST segment elevation in all leads, the working diagnosis was coronary dissection. Coronary angiography revealed a large interventricular septal rupture, confirmed by echocardiography. After discussion and as haemodynamics permitted, 6 weeks of medical observation were decided. A surgical repair was then performed, and provided a perfect repair of the shunt. We discuss about the prevalence and management of this rare traumatic complication.