In Italy plant extracts represent 8.6% of all pharmacological prescriptions for Benign Prostatic Hyperplasia (data from 1991). This review evaluates all the suggested mechanisms of action for plant extracts. Recently we demonstrated an antiestrogenic effect of Serenoa Repens in BPH patients. Clinical trials with plant extracts have yielded conflicting results. In a recent review by Dreikorn and Richter, only five placebo controlled studies were found. Moreover, as opposed to chemically defined drugs, it is possible that for these extracts the active ingredients are not known; consequently pharmacodynamic and pharmacokinetic data are often missing. The International Consultation of Benign Prostatic Hyperplasia (Paris, June 1991) concluded that, to date, phytotherapeutic agents must be considered as a symptomatic treatment. Now more adequate pharmacological and clinical studies, placebo controlled, should determine the exact role of these drugs in the treatment of BPH.