Until a few years ago, information regarding the epidemiology of resistant hypertension was obtained from indirect sources, such as cross-sectional studies on hypertension control in large cohorts from tertiary hypertension centers and outcome trials in hypertension. During the past 3 years, however, large population-based studies have provided direct epidemiologic data on resistant hypertension and estimated its prevalence at 8% to 12% of adult patients with hypertension. Chronic kidney disease (CKD), in particular, has been long considered a frequent underlying cause of resistant hypertension, however, recently, direct epidemiologic data for this entity in patients with CKD were brought to light again, suggesting an even higher prevalence of resistant hypertension (approximately 20%-35%) among such individuals. Furthermore, recent prospective cohort studies have suggested incident resistant hypertension to be associated with increased cardiovascular and renal risk in both the general hypertensive population and patients with CKD. This article discusses currently available data on epidemiology of resistant hypertension, providing a comparative overview of its prevalence, incidence, and prognosis in these two populations.