Between 1976 and 1988 in the United States, the secular trends to age-adjusted incidence rates of prostate cancer were significantly different by racial/ethnic group (P < 0.001), and increased significantly only among non-Hispanic Whites at a rate of 2.7 percent (95 percent confidence interval [CI] = 2.3-3.1%) annually. While incidence rates of regional disease increased significantly (7.7 percent to 11.3 percent annually) among all racial/ethnic groups during this period, localized disease increased significantly only among non-Hispanic Whites, by 1.8 percent (CI = 1.4-2.3%) annually. Prostate cancer mortality in Los Angeles County (California) remained constant among Hispanics, non-Hispanic Whites, and Asians, but increases 1.6 percent (CI = 0-3.2%) annually among Blacks. While the increase in localized disease rates of non-Hispanic Whites may be due to increased detection of asymptomatic disease, this apparently has not occurred among other racial/ethnic groups in Los Angeles County. The secular increase in regional disease rates among all racial/ethnic groups without a concurrent increase in mortality (except Blacks), suggests increased accuracy of staging rather than a true increase in incidence may account for these trends. Adjusted for socioeconomic status, year and age at diagnosis, Black and Hispanic men were at significantly higher risk of being diagnosed with non-localized disease (odds ratio = 1.39 and 1.24, respectively) than were non-Hispanic Whites.