The indications for and efficacy of non-hormonal drugs in the treatment of benign prostatic hyperplasia (BPH) are the subject of some controversy. However, a critical evaluation of the available literature shows that no clinically relevant reduction of prostatic size has been reached with any drug tested so far. It is suggested that alpha-adrenergic blockers exert a beneficial effect by reducing the "dynamic" component associated with prostatic obstruction. The application of objective criteria has not shown cholesterol-lowering and phytotherapeutic drugs to have any significant and clinically relevant advantage over placebos. The evaluation of drug therapy in BPH patients is complicated by the fact that the obstructive signs are masked by irritative symptoms ("prostatism", "unstable bladder"), the causes of which are also unknown. A causal drug therapy should have an impact on biochemically and/or biologically confirmed changes that are responsible for the development of BPH. Als long as the cause of BPH remains unknown, drugs cannot fulfil these requirements. The efficacy of drug therapy in patients with BPH can only, therefore, be evaluated in double blind controlled studies including modern urodynamic investigations. However, these standards should also be applied to the decision as to whether operative treatment is indicated and to evaluation of the results.