Background: Frailty is prevalent in older people and results from age-related decline in physiological function and reserve. The objective of this study was to validate the Hospital Frailty Risk Score (HFRS) in predicting outcomes and hospitalisation usage in older hospitalised heart failure (HF) patients. Methods: This study was a retrospective review of electronic medical records. Patients aged ≥65 years admitted with HF to a Singapore tertiary hospital between 1 January 2021 and 30 April 2021 were included. Patients were identified as HF patients in the value-driven care pathway and using ICD codes for HF. They were categorised into low risk (<5), intermediate risk (5–15) and high risk (>15) of frailty using the HFRS. Results: A total of 208 older patients with HF were included (mean age 79.4 years; 50.5% males). Using the HFRS, 35.1% were deemed at low risk, 46.2% at intermediate risk and 18.8% at high risk of frailty. Those at high risk of frailty were older than those at low risk (mean age 84.8 versus 76.5 years, respectively; p<0.001). Women had a higher risk of frailty than men. Univariate analyses showed longer length of stay (LOS) and higher 30-, 90- and 365-day mortality in those at high frailty risk. In multivariate analyses, HFRS was associated with long LOS, 90-day and 1-year mortality. Dementia, acute MI and renal disease were more common in high-risk patients. Comparing HFRS with the Charlson Comorbidity Index (CCI), HFRS was a better predictor of long LOS, mortality at 30, 90, 1 year and 30-day readmission than CCI. HFRS alone was a better predictor than combining the HFRS and CCI. Conclusion: Older patients with higher HFRS have increased healthcare utilisation, including longer LOS and higher mortality.