Cardiac insufficiency is one of the leading causes of mortality in the world and affects quality of life more than other chronic diseases. Cardiac self-efficacy can be considered for improving the quality of life of patients with this disease.  The purpose of this study was to determine the relationship between quality of life and cardiac self-efficacy in patients with heart failure.  This descriptive correlational study was performed on 227 patients with heart failure who referred to the cardiac clinics of Isfahan University of Medical Sciences affiliated hospitals, Iran, 2016-17. Sampling was done in a simple random way. The data gathering tool was comprised of three parts: demographic data questionnaire, Sullivan cardiac self-efficacy questionnaire, and Quality of Life questionnaire. Data were analyzed by SPSS software version 22.  The mean score of self-efficacy was 58.45 ± 25.92 and the mean score of satisfaction and importance of quality of life was 69.73 ± 18.72 and 82.76 ± 15.46, respectively. The results of this study showed that the importance of quality of life and satisfaction with quality of life are related to cardiac self-efficacy (P < 0.001). Pearson correlation coefficients showed a direct correlation between the scores of quality of life dimensions and the score of cardiac self-efficacy (in all cases, P < 0.001).  There is a positive and significant relationship between quality of life and cardiovascular self-efficacy in patients with heart failure.