Introduction: Frailty is commonly encountered in elderly patients with HF. However, the impact of both frailty and HF on outcomes in the population has not been delineated. There is a need for operationalizable definitions of frailty to explore variations in care among the elderly. Objective: To assess common indicators of frailty as predictors of mortality and rehospitalisation within 1 year in a population-based study of very elderly HF patients. Methods: Community-dwelling HF patients aged >75 yrs discharged from hospital or ED in Ontario, Canada, were studied using the Enhanced Feedback for Effective Cardiac Treatment and Emergency HF Mortality Risk Grade databases. Surrogates of frailty, including dementia, falls, incontinence, immobility, caregiver dependence, and abnormal weight loss, were identified from chart abstraction and linked hospitalization records. Survival analyses were performed using multiple Cox regression, for frail vs non-frail status and for each frailty component. Results: 9964 patients were identified (age 84±5 yrs). After adjustment for age, sex, vital signs, laboratory variables, and comorbidities, presence of any frailty indicator was associated with mortality: adjusted hazard ratio [HR] 1.18 (95%CI; 1.06-1.32, p=0.003). Frailty increased the risk of readmission and the association was more pronounced than for mortality (see Figure ): adjusted HR 1.29 (95%CI; 1.18-1.41, p<.001). Among the individual frailty components, significant predictors of mortality were: dementia (HR 1.49, 95%CI; 1.34-1.64, p<.001) and care provider dependency (HR 1.17, 95%CI; 1.01-1.36, p=0.038). In contrast, other frailty components increased the risk of readmission, specifically: falls (HR 1.17, 95%CI; 1.06-1.29, p=0.003) and incontinence (HR 1.64, 95%CI; 1.18-2.29, p=0.004). Conclusion: Frailty indicators derived from clinical and administrative data sources are associated with death and readmission in a very elderly HF cohort.