Cardiac trauma after blunt chest trauma is a rare complication of patients arriving alive to an emergency department. We here present the case of patient who had a partial rupture of the interventricular septum after having had a blunt chest trauma in a traffic accident. As there was no ventricular septal defect, conservative management was deemed appropriate. At 3-year follow-up, the patient was free of right heart failure symptoms suggestive of the septal defect progression.