Aims. To examine the relationship between activities of daily living (ADL) and readmission within 90 days and assess the cutoff value of ADL to predict readmission in hospitalized elderly patients with heart failure (HF). Methods. This cohort study comprised 589 consecutive patients with HF aged ≥65 years, who underwent cardiac rehabilitation from May 2012 to May 2016 and were discharged home. We investigated patients’ characteristics, basic attributes, and ADL (motor and cognitive Functional Independence Measure [FIM]). We analyzed the data using the unpaired t-test, χ2 test, Cox proportional hazard model, receiver operating characteristic (ROC) curve, and Kaplan-Meier method. Results. Of 589 patients, 113 met the criteria, and they were divided into the nonreadmission (n=90) and readmission groups (n=23). Age, body mass index, New York Heart Association class, hemoglobin level, and motor FIM score were significantly different between the two groups (p<0.05). The body mass index (hazard ratio [HR]: 0.87; p<0.05) and motor FIM score (HR: 0.94; p<0.01) remained statistically significant. The cutoff value for the motor FIM score determined by ROC curve analysis was 74.5 points (area under the curve = 0.78; p<0.001). Conclusion. The motor FIM score in elderly patients with HF was an independent predictor of rehospitalization within 90 days.