Inherited metabolic disorders are the cause of a small but significant number of sudden infant deaths in infants. We report on a boy who suddenly died at 10 months of age during an acute illness. Parents declined autopsy; nevertheless, they accepted a whole body MRI, which revealed hepatomegaly with steatosis. Acylcarnitine profile of a blood sample from neonatal Guthrie screening led to the diagnosis of type 2 carnitine palmitoyltransferase deficiency. To conclude, whole body MRI is useful in the investigation of some inherited metabolic causes of sudden infant death, which might prevent future deaths in the family. It is a good alternative when autopsy is refused.