ObjectivesWe aimed to determine the association between changes in nutritional status and the activities of daily living (ADL) at discharge, considering frailty status of older patients with heart failure (HF). MethodsThis study included 491 older inpatients with HF categorized into the following groups based on their clinical frailty scale (CFS) scores: low, intermediate, and high. Changes in nutritional status were assessed using the Controlling Nutritional Status score at admission and discharge. The outcome variable was Barthel Index (BI) at discharge. ResultsMultivariate logistic regression analysis indicated an association between improvement in nutritional status and high BI at discharge in both the low and intermediate CFS groups (odds ratio [OR], 2.18 [95% confidence interval, 1.04–4.58]), (OR, 2.45 [1.21–4.95]), respectively. ConclusionsImprovement in the ADL at discharge in older patients with HF was associated with improved nutritional status during hospitalization in the low and intermediate CFS groups.