Prostate cancer (PCa) is the most common newly diagnosed cancer among men in the United States today. With the advent of the prostate-specific antigen (PSA) test, the number of newly diagnosed cases has increased tremendously. The rates of PCa have increased so dramatically over the last decade that the age-adjusted incidence rate of PCa is no greater than that for any other cancer among men in the United States. Although PCa rates have risen steadily since 1973, there has been a dramatic acceleration in the late 1980s which has been associated with the introduction and use of PSA for screening and early detection. There is now some evidence that the rates may be levelling off and even decreasing in some areas. After lung cancer, PCa is the leading cause of death due to cancer in men in the United States. Although PCa can occur in younger men, it is essentially a cancer of elderly men. The highest rates of PCa in the world occur among African-American men in the United States. African-Americans have higher rates than Caucasians at all age levels in the United States, and adjusting for social-economic status does not appear to account for this difference to any appreciable extent. There is no clear reason why PCa rates are so much greater among African-Americans compared with Caucasians in the United States. The reported rates in Africans are substantially lower than those of an African-American, suggesting that environmental factors have an influence on PCa. In spite of this substantial impact on our society. PCa remains a relatively understudied disease, with an essentially unknown etiology. The reviews contained in this book are by no means exhaustive. We have, however, attempted to provide information regarding the pathology of prostate cancer, the status of diagnostic and prognostic markers, as well as a discussion of our understanding of the molecular basis for the disease.