Purpose: The purpose of this study was to examine the relationship between self-efficacy, social support, sense of community and health-related quality of life (HRQoL), including the direct and indirect effects of the variables on HRQoL. Methods: A cross-sectional survey was conducted with a convenience sample of 249 middle-aged and elderly residents living in a rural community in A-County, K Province. The structured questionnaire included 4 scales from the Euro Quality of life-5 Dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), and measures of General Self-Efficacy, Social Support, and Sense of Community. Data were analyzed using SPSS WIN 20.0 and AMOS 21.0 program. Results: The mean HRQoL score for the participants was $0.87{pm}0.13$. Self-efficacy (${eta}$=.13, p=.039) and age (${eta}$= -.38, p<.001) were significantly associated with HRQoL, explaining 21% of the variance. In the path analysis, self-efficacy showed a significant direct effect on HRQoL (${eta}$=.14, p=.040) and significantly mediating relationships between both social support (${eta}$=.05, p=.030) and sense of community (${eta}$=.02, p=.025) and HRQoL. Conclusion: Although self-efficacy was found to be the main predictor for HRQoL, the findings imply that social environmental factors such as social support and sense of community need to be considered when developing interventions to increase HRQoL in middle-aged and elderly residents in rural communities.