The usual ranges for prostate-specific antigen (PSA) are derived from a community-based population of White men but are used for screening on all men on the assumption that the differences between the PSA levels of different racial groups are small or have no clinical significance, Recently published reports, however, suggest that PSA levels in a specific racial population may vary directly with the relative risk of prostatic cancer within that population, PSA ranges were determined in Black and White men registered with the Veterans Affairs Maryland Health Care System, Baltimore, Maryland, The total patient census of 122,602 has near-equal numbers of Black and White men and maintains records of race designation for inpatients, Among the male patients with no known prostatic cancer, there were 10,808 men 40 years of age or older and 19,482 PSA test results, In this group, there were 3274 men identified as Blade, 2993 identified as White, Not of Hispanic Origin, and 4541 identified as Other Race or Race Unknown. The 95th percentile PSA values in Black men and White men 40 through 49 years of age were 2.80 ng/mL and 2.01 ng/mL, respectively; 50 through 59 years old, 5.40 ng/mL, and 4.19 ng/mL, respectively; 60 through 69 years old, 9.59 ng/mL and 7.00 ng/mL, respectively; 70 through 79 years old, 15.45 ng/mL, and 9.40 ng/mL, respectively; and for men older than 80 years of age, the 95th PSA values were 21.05 ng/mL in Black men and 18.25 ng/mL in White men, In every age group, Black men had a higher range (for the 95th percentile) than did White men, The largest difference was found in men 70 through 79 years old; in this age group, the ratio of the upper limit of PSA for Black men compared with White men was 1.6 ng/mL.