Complementary and alternative medicine (CAM) includes various practices, measures and products which are not presently considered to be a part of conventional (mainstream) medicine. Herbal products, vitamins, minerals and amino acids are increasingly popular as dietary supplements for the treatment, improvement and prophylaxis of urological diseases, and to improve general health and well-being. As these products are freely available without prescription, conventional healthcare providers are often unaware that their patients are using CAM. It is essential to know that some herbal supplements may act in the same way as chemical drugs, and that they originate 'from nature' does not mean that they are safe and/or with no potential harmful effects and/or toxicity. Eventual interactions with conventional medications and contamination with prescription drugs and metals have been reported. The active components of many phytotherapeutic preparations and their mechanism(s) of action are still being determined and evaluated. There is scientific evidence for the effectiveness of some CAM treatments, but for most there are important key questions yet to be answered through basic research and well-designed studies according to established guidelines. Because of the increasing popularity and use of CAM, conventional healthcare providers, including urologists, should not ignore it, and be well informed about the benefits and potential risks of dietary supplements, so that they can advise their patients about this developing field. Whenever necessary and possible, lifestyle and behavioural changes should be recommended before using CAM, and eventually be supplemented by CAM as a second step.