The authors present the case of a 56 year-old male, without medical history. He was driving his car and had the seatbelt fastened when he suffered a sudden deceleration. Immediately after the accident he felt a left sided laterocervical pain and at the level of the left hemithorax. During the following hours he experienced deglutition disturbances, dysarthria and tongue motility disturbances characteristic to a hypoglossal nerve paralysis. The paraclinical investigations performed subsequently, showed the dissection of the left internal carotid artery in the pharyngeal segment. The neurological treatment and the anticoagulant treatment led to the improvement of the symptoms up to their disappearance. The medico-legal consequence was granting a higher number of medical care days compared to the apparent lack of seriousness of the initial trauma. The conclusion is that minor traumas produced under different circumstances, such as aggressions, traffic accidents etc, can sometimes have an unexpected evolution, leading to severe complications, which have important medico-legal and legal consequences.