Diabetes and hypertension are the leading causes of renal failure. This study investigated racial differences in developing ESRD by participants' diabetes and hypertension status. This longitudinal study included 1,306,825 Medicare beneficiaries who were aged > or =66 yr at the study start and followed up to 10 yr from January 1, 1993, for the development of ESRD or death. During the 10 yr, 0.93 patients per 100 received ESRD treatment. After adjustment for age and gender, among patients with diabetes, black patients were 2.4 to 2.7 times and other races/ethnicities 1.6 to 1.7 times more likely than white patients to develop ESRD. Among hypertensive patients, black patients were 2.5 to 2.9 and others 1.7 to 1.8 times more likely than white patients to develop ESRD. Among patients with neither diabetes nor hypertension, black patients were 3.5 and others 2.0 times more likely. Black men with diabetes were 1.9 to 2.1 and women 2.5 to 3.4 times more likely than their white counterparts to develop ESRD. Hypertensive black men were 2.1 to 2.2 and women 2.8 to 3.6 times more likely to develop ESRD. The same findings were noted in women of other races/ethnicities. Compared with white counterparts, mortality was higher for black patients in all cohorts but lower among patients with ESRD. Although they are leading causes for renal failure, diabetes and hypertension do not cause racial differences in developing ESRD. Minority women especially are at greater risk for ESRD than white women. Further studies are needed to determine whether earlier initiation of dialysis is a factor in higher ESRD incidence among minorities.