Forty-four hirsute patients with polycystic ovary syndrome were randomly treated with finasteride (5 mg daily) or flutamide (250 mg twice daily) for 6 consecutive months. Hirsutism was evaluated before and after therapy with the Ferriman-Gallwey score and with measurement of hair diameter (micron). The hairs were taken from four different body areas: the face, abdomen, thighs and forearm. The measurement was carried out with a micrometer applied to the optical microscope. Mean plasma concentrations of luteinizing hormone, follicle-stimulating hormone, 17 alpha-hydroxyprogesterone, androstenedione, testosterone, free testosterone, dehydroepiandrosterone sulfate, insulin, and sex hormone binding globulin were determined before and after therapy. Hematochemical examinations and side-effects were controlled after the treatment. After 6-months' therapy, both antiandrogens significantly reduced the Ferriman-Gallwey score and hair diameter in all the body areas. Finasteride reduced the Ferriman-Gallwey score by 25% and hair diameter by 16-25%; flutamide reduced the score by 20% and hair diameter by 15.3-22%. Abdominal hairs were more sensitive to both drugs. Flutamide induced a significant drop in total testosterone and dehydroepiandrosterone sulfate. No important side-effect or change in the hematochemical parameters was observed. Our data demonstrate that finasteride and flutamide are effective in the treatment of hirsutism in patients with polycystic ovary syndrome.