Purpose : The purpose of this study was to identify factors influencing health promotion behavior in elderly people. Method: The participants in this study were 118 elders selected by convenience sampling in three cities. Data collection was done using questionnaires. The data were analyzed using descriptive statistics, Pearson correlation coefficients and stepwise multiple regression. Results : The results of this study are as follows : 1. Self efficacy and social support were found to have a statistically significant positive correlation with health promotion behavior, but depression was found to have statistically significant negative correlation with health promotion behavior. 2. Stepwise multiple regression analysis revealed that the most powerful predictor of health promotion behavior was depression. Depression, economic level, religion and social activity accounted for 34.9% of the variance in health promotion behavior in elderly people. Conclusion : According to these results, it is recommended that nursing interventions to decrease depression be developed in order to enhance health promotion behavior in elderly people.