Ethnic disparities in hypertension-related outcomes may relate to differences in medical care. This study assessed primary care sites serving low-income patients to determine if differences in process and treatment indicators might contribute to disparities in outcomes. Eight sites were enrolled with 100,000 patients, collectively. Trained nurses abstracted a random sample of medical records for diagnoses, laboratory data, medications, and demographic variables. Data were obtained on 1250 white and 2786 African-American adults. African Americans were more likely (p<0.01) to be hypertensive (44% vs. 23%) and diabetic (16% vs. 8%) than whites. African Americans were more likely to have serum creatinine, potassium, lipid, and glycosylated hemoglobin values recorded in the medical record than whites (p<0.01). African-American hypertensives were more likely (p<0.05) than white hypertensives to receive calcium channel blockers, angiotensin-converting enzyme inhibitors, diuretics, and combination therapy. Thus, there appeared to be little difference in the level of care between the two groups. Based on the sites examined, ethnic variations in important process and treatment indicators do not explain racial differences in cardiovascular and renal outcomes.