Fat embolism syndrome is a known complication in traumatology, especially in long bone fractures. The incidence of the fat embolism syndrome depends on the bone involved, whether fractures are isolated or multiple, the age of the patient, and the gender. It rarely occurs as a result of medical conditions. Classically, patients presents with a triad consisting of pulmonary distress, mental status changes, and petechial rash, occurred 24 to 48 hours after long-bone fracture. We present the case of an 88 year old woman, a victim of a traffic accident (pedestrian), who died in the same day. Autopsy and microscopic examination of fragments of tissue stained with Sudan III confirmed the presence of a multiorganic fat embolism in this case of post-traumatic fracture of the humerus.