Hirsutism is a male pattern of hair distribution in women. It may be caused by hypersecretion of androgens by the adrenal glands or the ovaries and/or by cutaneous sensitivity to circulating androgens due to hyperactivity of 5 alpha-reductase. The degree of hirsutism is evaluated and its cause suspected by physical examination, but the aetiological diagnosis is indicated by plasma testosterone essays: if the testosterone level is above 1.2 ng/mL, investigations must be made to find out whether hirsutism is caused by a virilizing tumour of the ovary or the adrenal gland, or by a congenital adrenal hyperplasia of late presentation. If the testosterone level is below 0.6 ng/mL, hirsutism is idiopathic. Between these two figures the conditions is often idiopathic, but the patient must be investigated for polycystic ovarian dystrophy, adrenal hyperplasia or tumour. Whenever possible, treatment is aetiological, but it is always symptomatic, consisting of electrical depilation of the face and, chiefly, antiandrogens (e.g. Androcur) associated with oestrogens. This treatment usually effective, and it has transformed the outcome of hirsutism, even when the disease is idiopathic.