Herein, we report the case of a 4-month-old male infant dying suddenly and unexpectedly. Post mortem examination was requested with clinical diagnosis of Sudden Infant Death Syndrome (SIDS). Histological examination showed instead the presence of an hemangioendothelioma located in the medulla oblongata. Sudden unexpected death is the commonest form of death among babies between 1 month and 1 year of age. Although the vast majority of these fatalities are related to SIDS, a very small percentage is due to primary neoplasm. Necroscopy studies of sudden infant death should always include an accurate histological examination of the medulla oblongata on serial sections but seldom do.