Nutrition label use among patients with coronary heart disease (CHD) is limited. This study aims to investigate the mediating effect of dietary self-efficacy on the relationship between health literacy and nutrition label use in CHD patients. This cross-sectional study recruited 350 CHD patients using convenience sampling from two hospitals in Changsha City. Data were collected using a general information questionnaire, the Newest Vital Sign Scale, the Cardiac Diet Self-efficacy Scale, and the Nutrition Label Use Questionnaire. SPSS 25.0 was used for Pearson correlation analysis and multiple linear regression analysis, while Model 4 in the SPSS macro program PROCESS was applied for mediation effect analysis. The results indicated health literacy and dietary self-efficacy were positively and significantly correlated with nutrition label use in CHD patients (P <
0.002). Bootstrap test results demonstrated that dietary self-efficacy partially mediated the relationship between health literacy and nutrition label use, with a mediation effect of 0.184 (95% CI: 0.144-0.225), accounting for 55.42% of the total effect. In conclusion, dietary self-efficacy mediates the relationship between health literacy and nutrition label use in CHD patients. Targeted interventions that address both health literacy and dietary self-efficacy are crucial for improving nutrition label use among CHD patients.