This study aims to explore the association between the frailty index and chronic heart failure (CHF). We collected data from the National Health and Nutrition Examination Survey (NHANES) (1998-2018) database to assess the association between CHF and frailty. Demographic, inquiry, laboratory examinations, and characteristics were gathered to compare CHF and non-CHF groups. Multiple logistic regression analysis was performed to explore the relationship between frailty and CHF. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence interval (CI) for mortality from all causes and cardiovascular disease (CVD). A total of 16,175 participants with cardiac and cerebrovascular disease were categorized into CHF (n = 1,125) and non-CHF (n = 15,050) groups. In patients with CHF, the prevalence of frailty, pre-frailty, and non-frailty were 66.31, 30.93, and 2.75%, respectively. In multiple logistic regression, patients with CHF who were male (OR = 0.63, 95% CI: 3.11-5.22), whose annual family income was over $20,000 (OR = 0.52, 95% CI: 0.37-0.72, p < 0.001), or with normal hemoglobin level (OR = 0.77, 95% CI: 0.68-0.88, P < 0.001) had a lower likelihood of frailty. CHF patients with hypertension (OR = 3.60, 95% CI: 2.17-5.99, P < 0.0001), coronary heart disease (OR = 1.76, 95% CI: 1.10-2.84, P = 0.02), diabetes mellitus (OR = 1.89, 95% CI: 1.28-2.78, P < 0.001), and stroke (OR = 2.52, 95% CI: 1.53-4.15, P < 0.001) tended to be frail. Survival analysis suggested that pre-frailty and frailty were related to poor all-cause deaths (HR = 1.48, 95% CI: 1.36-1.66; HR = 2.77, 95% CI: 2.40-3.18) and CVD mortality (HR = 1.58, 95% CI: 1.26-1.97; HR = 2.55, 95% CI: 2.02-3.21). CHF patients with frailty were strongly connected with all-cause death (HR = 2.14, 95% CI: 1.27-3.62). Frailty was positively associated with CHF. Patients with CHF who were male, whose annual family income was over $20,000, or with normal hemoglobin level were negatively correlated to frailty. For patients with cardiac and cerebrovascular disease as well as CHF, frailty was strongly connected with all-cause death.