Frailty is a common geriatric syndrome characterized by increased risk of disability, hospitalization, and mortality. Hypertension (HTN) is one of the most common chronic medical conditions in the elderly. However, there have been few studies regarding the association between frailty and HTN prevalence, treatment, and control rates. We analyzed data of 4,352 older adults (age ≥ 65 years) from the fifth Korea National Health and Nutrition Examination Survey. We constructed a frailty index based on 42 items and classified participants as robust, pre-frail, or frail. Of the subjects, 2,697 (62.0%) had HTN and 926 (21.3%) had pre-HTN. Regarding frailty status, 721 (16.6%), 1,707 (39.2%), and 1,924 (44.2%) individuals were classified as robust, pre-frail and frail, respectively. HTN prevalence was higher in frail elderly (67.8%) than pre-frail (60.8%) or robust elderly (49.2%) (P < 0.001). Among hypertensive patients, frail elderly were more likely to be treated than pre-frail or robust elderly (P < 0.001), but the proportion of patients whose blood pressure was under control ( < 150/90 mmHg) was lower in frail elderly (P = 0.005). Considering the adverse cardiovascular outcomes associated with frailty, more attention should be paid to the blood pressure control of the frail elderly.