Abstract Background Self-management in patients with heart failure is important in terms of their prognosis and quality of life. The use of mobile applications in the self-management of patients with heart failure has been suggested to improve their knowledge of the disease and quality of life. However, there are limited data on the experiences of patients with heart failure when mobile applications are integrated into their routine as a self-management intervention. Purpose We aimed to determine the experiences of patients with heart failure who incorporated the use of mobile applications as a self-management intervention. Methods In this qualitative cross-sectional study, participants were purposive-sampled at a university hospital, and semi-structured interviews were conducted with both male and female patients, aged 40–70 years, with a diagnosis of chronic heart failure (ACCF/AHA stage C). Data were collected between December 2022 and April 2023. All interviews were audio-recorded and transcribed verbatim, followed by content analyses. The mobile application used in this study recorded and managed patients’ subjective symptoms and daily life as cloud data and allowed healthcare professionals to access the data using a dedicated terminal. Results Four themes were identified from the data: 1) patients used the mobile application in their own way through trial and error; 2) the support of healthcare professionals through the mobile application increased patients’ sense of self-efficacy; 3) using the mobile application made them feel secure as they always felt connected; and 4) some patients struggled to incorporate new technology into their self-management. Most participants in this study had a positive experience of using the mobile application for self-management in their own way with the support of healthcare professionals, including gaining a sense of self-efficacy and security. On the other hand, some patients had a negative experience, such as not looking at the mobile application for a while or discontinuing self-management because they felt burdened by the introduction of this new self-management method. Conclusions Both positive and negative aspects of the experiences of patients with heart failure with adopting a mobile application for self-management were identified. Psychological support is essential when patients incorporate mobile applications into their routine as a self-management intervention.