Anorexia nervosa is an eating disorder characterized by deliberate weight loss, with an average prevalence of 0.5% for girls and younger women aged 12-30 years and 0.05% for men aged 12-30 years. The etiology of the disorder is not fully established, but most authors risk factors are divided into biological, psychological, developmental and sociocultural. Anorexia is divided into restrictive which is characterized by occasionally reducing diet and pigging / physic that with a diet is characterized by occasional overeating and emptying of food from the body with laxatives or vomiting. The diagnosis of anorexia nervosa is used two official classifications: International Classification of Diseases (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Treatment includes short-term interventions to increase body weight, save lives and to improve the long-term psychological functioning and prevent relapse, and they achieve with an appropriate form of therapy and in certain conditions. With treatment are important preventive measures that can remove the factors that cause disorder, early detection and treatment of disease. In Croatia there are groups Libella, Hope (Nada) and Bea that providing assistance to those who suffering from eating disorders and their families, carried out prevention programs and educate the public.