Studies which evaluate the psychosocial development and integration of adult female congenital adrenal hyperplasia (CAH) patients are rare but show that patients with the salt wasting form are significantly more virilized and more frequently single and childless. Major complaints are irregular menstruation, hirsutism, acne, obesity, deep voice, and cushingoid features. Surprisingly, a higher prevalence of psychosomatic disorders has not yet been described. Since anorexia nervosa (AN) has not yet been described in patients with CAH, we here report 4 cases of female CAH patients who developed AN during adolescence. Diagnosis of CAH was made between the age of 10 days and 3 years. Three patients suffer from the simple-virilizing form of CAH, one patient has a mild salt wasting CAH. Genital malformation varied from Prader stage II to IV. All 4 patients were compound heterozygotes for mutations/deletions of the CYP21B gene. Control of substitution therapy consisting of hydrocortisone and fluorocortisone was good. AN developed at ages 12, 13, 17, and 21 years (ICD 10 criteria for AN are BMI below 17.5 kg/m2, deliberate weight loss, body image disturbance, and primary or secondary amenorrhoea). Diagnosis of AN was established by psychiatrists and/or psychologists. All four patients showed an impressive and deliberate weight loss between 13 and 20 kg within 6 months, had primary or secondary amenorrhoea, and presented with BMI between 13 and 17.9 kg/m2. All patients received psychological treatment and recovered. However, one patient had a severe relapse of AN. Two patients are now married and one has a healthy son. These cases demonstrate that the diagnosis of CAH is compatible with the development of AN and illustrate the importance of providing treatment for CAH patients that encompasses not only medical but also psychological and social care.