Purpose: The prevalence of frailty among patients with heart failure is about 45%. Frailty may result in patients' functional decline, falls, disability, and decreased quality of life. Qualitative studies can explore older patients' perceptions of frailty and help patients cope with it. However, a qualitative approach that explores the experience of frailty in older patients living with heart failure is lacking. This study aimed to explore the lived experience of frailty in older patients with heart failure. Methods: This qualitative study applies Giorgi's phenomenological method. Data were collected from October 2019 to August 2020. Thirteen older patients with heart failure aged at least 60 years were recruited using purposive sampling from a medical center in Taiwan. The participants participated in an in-depth interview using a semistructured interview guide. Results: Seven themes were identified: “being reborn at the end of the road but having difficulty recovering”, “living with a disease with an ineffable feeling”, “feeling like being drained: physical weakness and a dysfunctional body”, “struggling with impaired physical mobility and facing unexpected events”, “suffering from mental exhaustion”, “receiving care from loved ones”, and “turning over a new leaf”. Conclusions Frailty in older patients with heart failure was obscure and difficult to describe. Frailty could be improved by medical intervention, self-management, and social support but was difficult to reverse. Patients with heart failure should be evaluated for frailty using multidimensional assessment tools at first diagnosis and provided frailty-related information so that patients have proper insight into their disease as early as possible.