The purpose – This research aims to investigate responsible environmental behavior intention of travelers formed upon visiting ecotourism sites in Indonesia. Nowadays, ecotourism has become a popular concept of tourism in Indonesia due to its rich potential of natural and cultural resources. Nevertheless, it is undeniable that not all travelers visiting ecotourism objects demonstrate positive environmental behavior. Several previous studies have already revealed that travelers’ behavior may alter after visiting tourism sites. Unfortunately, there has not been much discussion on travelers’ positive behavior formed after visiting an ecotourism site. In this research, four variables regarded as significant in shaping responsible environmental behavior intention included destination image, trip quality, perceived value, and satisfaction. Design/Methodology – This research applied a survey method. The research sample consisted of travelers who had visited ecotourism sites in Indonesia, while the number of respondents amounted to 210 travelers. Structural Equation Modeling (SEM) was selected as the technique of analysis. Finding – This research confirmed that five proposed hypotheses were supported. Hence, this study clearly contributes to the development of the theory and concept of ecotourism useful for practitioners associated with ecotourism activities. Originality of the research – Research on ecotourism in developing countries has not been much done. Similarly, the research on ecotourism related to intention to behave environmentally responsible is still not much to investigate, while the ecotorurism activities in Indonesia began in earnest. Therefore, research is expected to contribute ideas and implementation of ecotourism in developing countries.