Prostate cancer incidence and mortality rates vary worldwide. In the United States, prostate cancer is the most common malignancy affecting men and is the second-leading cause of cancer death. Risk of developing prostate cancer is associated with advancing age, African American ethnicity, and a positive family history, and may be influenced by diet and other factors. The incidence of prostate cancer increased sharply after the introduction of widespread screening for prostate-specific antigen (PSA), although rates have now returned to levels seen before that time. PSA screening has been associated with a shift toward diagnosis of earlier-stage disease, but this has not been accompanied by a shift toward a lower histologic grade. Although overall prostate cancer mortality rates decreased during the 1990s, it was largely because of reductions in deaths among men diagnosed with distant disease. In contrast, mortality rates for men diagnosed with localized or regional disease increased gradually during most of the 1990s before decreasing slightly among white men and reaching plateaus among African Americans.