Self-mutilation in the context of factitious disorder can lead to prolonged and complicated treatment in every medical field. Because of a prevalence of 1-5% in hospitalised patients, it is important to be aware of this disorder to protect patients from self- and foreign-induced harm. Often the patient history gives important hints. The different manifestations of this disorder, the specific doctor-patient relationship, several techniques of confrontation and current treatment are presented. Clinical cases from the fields of hand and plastic surgery are presented.