This is a report on a 30-year-old black man who suddenly died in the worker transportation vehicle in which he had been quietly sitting for thirty minutes. No information about his medical or surgical history or any family history has been obtained. This case is intended to highlight the fact that forensic autopsy is a valuable tool to recognize the cause of death and that fatal pulmonary thromboembolism still remains a post-mortem diagnosis. In this case report, the autopsy found a fresh saddle pulmonary thromboembolus associated with partially organized thrombi of the inferior vena cava. Can a prolonged seated position encourage thrombus formation? We think that seat-related factors and especially patient-related factors intervene together in the development of thromboembolic events. In our medico-legal unit, having no means to search for these factors, we speculated on the various causes that could be involved in the occurrence of venous thromboembolism in our subject. We emphasize the importance of focusing research on genetic factors and the impact of traditional medicine in African people.