To establish nationwide projections for hypertension-related renal disease among middle-aged residents of the United States and compare disease burden in demographic subgroups. Integrated analysis of data from the US Census, the National Health and Nutrition Examination Survey of 1976 through 1980 (NHANES II), the 1971 through 1975 NHANES I Epidemiologic Follow-up Study, the Hypertension Detection and Follow-up Program trial, and the US Renal Data System. African-American and white residents of the United States, aged 30 to 69 years. Incidence rates and counts of hypertension, hypertension-related hypercreatinemia, and hypertension-related end-stage renal disease (ESRD). Each year, approximately 1.8 million middle-aged Americans develop hypertension, 140,000 develop hypertension-related hypercreatinemia, and 5300 develop hypertension-related ESRD. African Americans are at increased risk for hypertension (relative risk [RR], 1.6; population-attributable risk [PAR], 5%), hypercreatinemia if hypertensive (RR, 2.4; PAR, 18%), ESRD if hypertensive with hypercreatinemia (RR, 2.7; PAR, 32%), and hypertension-related ESRD overall (RR, 8.0; PAR, 44%). Compared with women, men are at increased risk for hypertension (RR, 1.3; PAR, 13%) and hypertension-related ESRD (RR, 1.6; PAR, 23%). Most cases of hypercreatinemia in hypertensives (73%) occur among those with mild hypertension. Progression to ESRD is rare in persons with hypertension-related renal disease, and factors other than blood pressure probably play an important role. A large proportion of hypertension-related renal disease cases occur among population subgroups considered to be at low risk. Interventions that favorably influence factors associated with the progression of hypertension-related renal disease in African Americans, in men, and in persons with mild hypertension, hold the greatest potential for reducing the population burden of hypertension-related ESRD.