In forensic medicine, the neck is a specific area par excellence, the site of a multitude of violence, most often fatal. Cervical self-aggression is a dangerous act of self-destruction with serious consequences. The self-mutilator, is a person with mental difficulties and should receive adequate psychiatric care.The diagnosis of self-mutilation is first medico-legal, entitled within the framework of a medico-judicial procedure, well defined but incomplete, it will only be when the forensic doctor directs the self-mutilator for specialized care in psychiatry. My objective in this work is to show through a clinical case the interest of medico-legal and psychiatric cooperation in the management of self-aggressive violence, for the interest of the patient and in the service of health public.