Background Cardiac self-efficacy determines how people feel, think, motivate themselves and behave with regards to improving their cardiac health subsequently preventing complications of coronary artery disease (CAD). Given almost one-third of global death is contributed by CAD with 10% of disability adjusted life years lost in low- and middle-income countries (including Nepal), it is important to identify factors that can promote cardiac self-efficacy. There are no studies in Nepal focusing on predictors of self-efficacy. Therefore, we aim to determine the predictors of cardiac self-efficacy of CAD patients in Nepal. Design and methods This is a cross-sectional study where we recruited 170 patients (≥30 years) diagnosed with CAD from two tertiary level hospitals. Multiple linear regression model was used to identify the predictors of cardiac self-efficacy. Results The mean age of the participants was 60.45±10.39 years (range, 31-83). Most of the participants were diagnosed as myocardial infarction (91.2%), rest with unstable angina (6.5%) and stable angina (2.4%). The multivariate analysis shows age (p<0.001), health behaviors (p<0.001) and knowledge of the disease (p<0.001) were statistically significant predictors to cardiac self-efficacy. Every 1-year increase in age was associated with 0.23 units increase in cardiac self-efficacy score. Similarly, every unit increase in health behavior score and knowledge of disease score was associated with 0.432 units and 0.475 units increase in cardiac self-efficacy score respectively. Conclusion Age and health behaviors were the strongest predictors of cardiac self-efficacy followed by knowledge of the disease. We conclude that those with poor health behavior are at a greater risk of poorer cardiac self-efficacy compared to those with relatively good level of self-efficacy. Public health interventions such as awareness raising about cardiac disease and health behavior modification along with early screening, diagnosis and appropriate care are essential to improving self-efficacy and cardiac care outcomes.