Prostate cancer is a public health problem. Currently, it is the most frequent cause of cancer, and the second most common cause of cancer mortality, in men in most developed countries. Its incidence in France in 2000 is close to 40 000 new cases, a consistent increase of 7,9% per year. One man in 8 in France will be diagnosed with prostate cancer in the course of his life. More than half of these cancers are diagnosed before 75 years, most often at a localized stage accessible to a curative treatment. The increasing practice of PSA testing and systematic prostatic biopsies are responsible for this rise in incidence. The mortality is stable at around 10 000 per year in France. Hereditary risk factors permit a definition of a target population for screening. Environmental factors are little known, but a diet rich in fat seems to be associated with a more elevated risk.