US researchers examined the available data from clinical trials for certain botanicals used for lower urinary tract symptoms secondary to benign prostatic hyperplasia, including Serenoa repens (saw palmetto), Prunus africana (= Pygeum africanum, African plum), Secale cereale (rye pollen) and Hypoxis rooperi (South African star grass). Medline and the Cochrane Library were searched in June 2007 using the terms benign prostatic hyperplasia, lower urinary tract symptoms, phytotherapy, saw palmetto, Serenoa, Permixon, Pygeum africanum, Tadenan, Cernilton, Cernitin and Hypoxis. Search results were assessed for relevance and the inclusion of placebo-controlled trials. Two systematic reviews and three clinical trials were examined in the evaluation of S. repens. Data from the systematic reviews showed an improvement in flow rates and symptoms. The results of one clinical trial were equivocal and the remaining two trials clearly showed equivalence to placebo. Systematic reviews were used in the evaluation of P. africana, S. cereale and H. rooperi. P. africana and H. rooperi showed an improvement in flow rates and symptoms compared to placebo, while S. cereale showed an improvement in symptoms but not flow rates compared to placebo.