Purpose: This study aimed to examine the levels of e-Health literacy, self-efficacy, job stress, and health-promoting behaviors among middle-aged workers and to identify factors associated with their health-promoting behaviors. Methods: This was a descriptive survey conducted among 139 middle-aged workers. Data were collected from March 10 to 20, 2026, through an online survey agency targeting middle-aged workers aged 40 to 64 years. Data were analyzed using descriptive statistics, t-tests, ANOVA, Scheffe’s test, Pearson correlation coefficients, and hierarchical multiple regression analysis. Results: The mean score for e-Health literacy was 3.73±0.79, self-efficacy was 3.64±0.68, job stress was 3.02±0.57, and health-promoting behaviors was 2.47±0.51. Hierarchical multiple regression analysis showed that e-Health literacy (β=.38, p<.001), good subjective health status (β=.33, p=.001), job stress (β=.26, p<.001), and self-efficacy (β=.18, p=.030) significantly predicted health-promoting behaviors. The final model explained 56.0% of the variance in health-promoting behaviors. Conclusion: To improve health-promoting behaviors among middle-aged workers, it is necessary to develop workplace-based health promotion programs that strengthen e-Health literacy and self-efficacy while considering workers’ health status and job stress levels.