Prostate cancer is one of the most common malignancies in the world; more and more men are being diagnosed with prostate cancer worldwide. According to epidemiological studies, prostate cancer will become the most common male cancer by 2010, with 900,000 cases per year. Nevertheless, although the constant increase in incidence, knowledge about the aetiology and risk factors of this tumour is still poor. Several important issues could foster the understanding and prevention of this disease, such as the variation in incidence of prostate cancer between ethnic populations, studies on migrants, dietary and genetic factors. Here we provide an update on epidemiology and risk factors of prostate cancer.