Sexsomnia is a disorder that is characterized by abnormal sexual behaviours during sleep and can vary from explicit sexual vocalizations to violent masturbation and complex sexual acts including oral, vaginal or anal penetration. This disorder has clinical, psychosocial and medico-legal consequences, both to the patient and the people that surround him. Despite the scarce literature and infrequent reports, there are some descriptions of violent behaviours, sexual assault and sexual involvement of minors. Whenever we suspect that a patient suffers from sexsomnia, we must write a rigorous and complete clinical history, make a neurologic and phychiatric evaluation and nocturnal videopolysomnography. As soon as the diagnosis is established, we must plan treatment approaches. More attention should be payed to the psychosocial and medico-legal issues, and new research is needed to provide for better understanding of etiology and to improve the clinical evaluation and management.