The environment has gotten the main concern of people with the increase in customer awareness and knowledge of social welfare. The importance of environment, increase in laws and regulations, intense competition between organizations and the pressure of public have forced companies not only to pay attention to sales and profit but also to the environment and customers' health. Companies can survive that pay attention to their social missions. For this reason, this paper investigates the effect of green marketing on customers' purchase intention with the mediating role of social responsibility and product image. We used Lisrel to analyze the 384 customers which are surveyed through a questionnaire. Results show that all the hypotheses are supported except the direct effect of green marketing on customers' purchase intention. Therefore, green marketing has an impact on customers' purchase intention through product image and social responsibility.