The development and introduction in clinical practice of finasteride, the first potent inhibitor of steroid 5-alpha-reductase that inhibits the conversion of testosterone to its active form dihydroxytestosterone, has created the possibility to prevent and treat prostatic disorder by manipulating and lowering the androgens levels in the prostate. Randomised and placebo-controlled trials have demonstrated the benefit of finasteride in men with enlarged prostatic gland owing to benign prostatic hyperplasia in terms of symptoms and urinary flow rate improvements. The Prostate Cancer Prevention Trial has clearly stated the chemopreventive properties of finasteride for prostate cancer but the necessity to provide such preventive therapy to a specific group of men with a higher risk to develop a clinically significant disease is under discussion. Finasteride is administered orally as a single daily dose. We recommend a 5 mg dose.