PURPOSE Black Americans with hypertension have poorer blood pressure control than their white counterparts, but the impact of this disparity on mortality among black adults is not known. We assessed differences in systolic blood pressure (SBP) control among white and black adults with a diagnosis of hypertension, and measured the impact of that difference on cardiovascular and cerebrovascular mortality among blacks. METHODS Using SBP measurements from white and black adults participating in the NationalHealth and Nutrition Examination Survey, 1999-2002, we modeled changes in mortality rates resulting from a reduction of mean SBP among blacks to that of whites. Our data source for mortality estimates of blacks with hypertension was a meta-analysis of observational studies of SBP; our data source for reduction in mortality rates was a meta-analysis of SBP treatment trials. RESULTS The fi nal sample of participants for whom SBP measurements were available included 1,545 black adults and 1,335 white adults. The mean SBP among blacks with hypertension was approximately 6 mm Hg higher than that for the total adult black population and 7 mm Hg higher than that for whites with hypertension. Within the hypertensive population, a reduction in mean SBP among blacks to that of whites would reduce the annual number of deaths among blacks from heart disease by 5,480 and from stroke by 2,190. CONCLUSIONS Eliminating racial disparity in blood pressure control among adults with hypertension would substantially reduce the number of deaths among blacks from both heart disease and stroke. Primary care clinicians should be particularly diligent when managing hypertension in black patients.