Many studies report that hypertension (HTN) prevalence is higher (at least 30%) and its outcomes generally worse among African Americans (AA) with prevalence and outcome disparities increasing with advancing age and body mass index (BMI). Data also have shown a higher likelihood of poor HTN control among AAs. However, few studies have examined the prevalence of HTN or the levels of awareness, treatment, and control among all-AA, population-based samples. The Jackson Heart Study (JHS), an epidemiological cohort study of 5302 AAs residing in the Jackson Mississippi Metropolitan Statistical Area who were examined between the fall of 2000 and early 2004, offers an opportunity to analyze important aspects of the HTN epidemic in AAs. HTN was defined using JNCVII cutpoints and/or use of antihypertensive medications in the past 2 weeks. Awareness was assessed with standardized questions. Control was defined as treatment with antihypertensive medication and a measured blood pressure of <140/90 mmHg or <130/80 for diabetic hypertensives. Overall, 62% (3258 of 5302) of the JHS cohort had HTN. HTN prevalence increased with age (81%, 1677 of 2081, among those aged 60+) and among women (64%; 2132 of 3361). In stepwise logistic regression analysis, increasing age, BMI, presence of diabetes (using ADA cutpoints and/or use of glycemic medications), presence of self-reported cardiovascular disease, and current alcohol use were associated with the presence of HTN. Overall, 86% (2800 of 3258) were aware of their HTN, and among those who were aware, HTN was treated in 80% and controlled in 64% (1661 of 2604). Among diabetics, HTN was controlled in 39% (287/741). Previously unknown HTN was identified in 6% (313 of 5302) of the cohort, 80% (249 of 313) of whom fell within the JNCVII Stage I designation. HTN prevalence in this recently examined population-based, all-AA, Southern US cohort is high-almost twice the reported NHANESIII prevalence for non-Hispanic blacks. However, awareness and treatment rates are higher, while control rates are over double the control rates generally quoted for AAs in other studies. Age-specific data demonstrate lower levels of control among men and those aged 60+, and poor control among diabetic hypertensives.