Introduction:HTN and higher arterial stiffness are more common among self-reported black individuals compared to whites. The degree to which genetic African ancestry accounts for racial disparities in these phenotypes is not well known.Methods:Self-identified black participants from the Dallas Heart Study (DHS) free from CVD with available genotyping (Infinium HumanExome, Illumina) and arterial stiffness assessment by cardiac MRI were included. Genetic ancestry proportions were quantified from genome-wide genotyping data. Multivariable linear regression models were used to assess the association of African ancestry with arterial stiffness parameters [aortic pulse wave velocity (PWV), proximal aortic impedance (Zc), pulse pressure (PP)]. Among participants free from HTN at baseline, the association of African ancestry with HTN at follow-up 7 years later was assessed using adjusted logistic regression models.Results:The cohort included 1120 self-identified black participants (mean age 45y, 57% women) with a mean African ancestry proportion of 86% (SD 9%). In adjusted analyses, proportion of African ancestry was not significantly associated with arterial stiffness (PWV, Zc & PP) [Table]. In contrast, among participants free from HTN at baseline, a higher proportion of African ancestry was significantly associated with higher odds of HTN on follow-up independent of age, sex, SES factors, and CV risk factors (Table).Conclusions:Among self-reported black participants, higher proportion of genetic African Ancestry was associated with higher odds of HTN independent of biological and SES factors. However, African ancestry was not associated with measures of arterial stiffness. Genetic ancestry accounts for at least part of the higher burden of HTN but not arterial stiffness in black individuals. Future studies are needed to confirm these findings and better understand the contribution of genetic factors toward racial disparities in hypertension.