Background Blood pressure control is a paramount goal in secondary stroke prevention; however, high prevalence of uncontrolled blood pressure and use of multiple antihypertensive medication classes in stroke patients suggest this goal is not being met. We determined the prevalence and factors associated with apparent treatment-resistant hypertension in persons with/without stroke or transient ischemic attack. Methods Data came from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study, a national, population-based cohort of 30,239 black and white adults aged â‰¥ 45 years, enrolled 2003-2007, restricted to 11,719 participants with treated hypertension. Apparent treatment-resistant hypertension was defined as (1) uncontrolled blood pressure (systolic â‰¥ 140 mm Hg or diastolic â‰¥ 90 mm Hg) with â‰¥ 3 antihypertensive medication classes, or (2) use of â‰¥ 4 antihypertensive medication classes, regardless of blood pressure level. Poisson regression was used to calculate characteristics associated with apparent treatment-resistant hypertension. Results Among hypertensive participants, prevalence of apparent treatment-resistant hypertension was 24.9% (422 of 1694) and 17.0% (1708 of 10,025) in individuals with and without history of stroke or transient ischemic attack, respectively. After adjustment for cardiovascular risk factors, the prevalence ratio for apparent treatment-resistant hypertension for those with versus without stroke or transient ischemic attack was 1.14 (95% confidence interval, 1.03-1.27). Among hypertensive participants with stroke or transient attack, male sex, black race, larger waist circumference, longer duration of hypertension, and reduced kidney function were associated with apparent treatment-resistant hypertension. Conclusions The high prevalence of apparent treatment-resistant hypertension among hypertensive persons with history of stroke or transient ischemic attack suggests the need for more individualized blood pressure monitoring and management.