BackgroundIn hemodialysis, as a choice of treatment due to long treatment duration, the patient encounters limitations. Perceived social support, perceived self-efficacy and health promoting activities are important strategies to facilitate and maintain their health.AimTo determine the correlation between social support, self-efficacy and health promoting behaviors in hemodialysis patients hospitalized in Karaj city in 2015.MethodsThis cross-sectional descriptive correlational study was carried out on 200 hemodialysis patients who were selected from four hospitals in Karaj based on cluster sampling. Data were collected using these methods: “General Questionnaire”, “Perceived Self-Efficacy Scale”, “Multidimensional Perceived Social Support Scale” and “Health-Promoting Lifestyle Profile 2”. Data were analyzed by SPSS version 22 and the EQS 6.1. Independent t-test, Mann-Whitney U, Kruskal-Wallis test, spearman correlation coefficient was used to analyze the data. To determine the relation between perceived self-efficacy, perceived social support and health promoting behavior, structural equation modeling was applied.ResultsSelf-efficacy has a significant positive correlation with social support (r=0.592, p<0.001) and significant negative correlation with health-promoting behaviors (r=−0.709, p<0.001), and social support has a significant negative correlation with health-promoting behaviors (r=−0.709, p<0.001). Also, results showed that perceived self-efficacy had a greater role than perceived social support in explaining health-promoting behaviors.ConclusionThe relationship between health promoting behaviors, self-efficacy and social support reveals a necessity for Community Health Nursing planners, matrons and hospital managers and nurses to pay more attention to the needs of patients under hemodialysis. It is recommended that due to some unexpected findings in this study, further studies shall be fulfilled on the factors effective on the discussed variables.