Background and Purpose - Stroke mortality is higher in the "Stroke Belt" and among blacks in the United States. Because hypertension is the leading risk factor for stroke, hypertension management (raising awareness, increasing treatment, and improving control) may reduce these disparities. Methods - Hypertension awareness, treatment, and control were measured in the REasons for Geographic And Racial Differences in Stroke study, a national population-based cohort of black and white participants >45 years of age. At the time of this report, 11 701 had been enrolled. Racial differences and geographic differences (between the Stroke Belt and other regions of the United States) were described. Results - Black participants were more aware than whites of their hypertension (odds ratio [OR], 1.31; 95% CI, 1.07 to 1.59) and more likely to be on treatment if aware of their diagnosis (OR, 1.69; 95% CI, 1.40 to 2.05), but among those treated for hypertension, they were less likely than whites to have their blood pressure controlled (OR, 0.73; 95% CI, 0.64 to 0.83). There was no evidence of a difference between the Stroke Belt and other regions in awareness of hypertension (OR, 0.95; 95% CI, 0.79 to 1.14), but there was a trend for better treatment (OR, 1.15; 95% CI, 0.97 to 1.37) and control (OR, 1.11; 95% CI, 0.98 to 1.30) in the Stroke Belt region. Conclusions - These findings suggest that interventions to improve blood pressure control among blacks are promising to reduce the racial disparity in stroke mortality. The lack of substantial geographic differences in hypertension awareness and the trend toward better treatment and control in the Stroke Belt suggest that differences in hypertension management may not be a major contributor to the geographic disparity in stroke mortality. © 2006 American Heart Association, Inc.