In the United Kingdom, there has been a steady decline in the number of conventional autopsies performed in children. For cardiovascular disease, structural and not pathological considerations are often more important in defining the cause of death. Magnetic resonance imaging is now often used in the assessment of congenital cardiac malformations during life. In this case report, we demonstrate how post-mortem magnetic resonance imaging was able to establish the diagnosis of aortic rupture in a patient who had undergone surgical repair of aortic interruption. In this patient, the parents had declined conventional histopathological autopsy, but were happy to consent to magnetic resonance post-mortem assessment.