Although nature-based tourism is often promoted as benefiting local destinations through income generation, employment, and direct conservation support, it is also believed to influence tourists’ environmentally friendly attitudes, knowledge, and ultimately their behavior. Yet, few studies have empirically documented these outcomes, and those that do are inconsistent in the variables measured and the time frame analyzed. This paper examines the empirical research on nature-based tourism's ability to foster long-term stewardship behavior among travelers by conducting a systematic review of peer-reviewed tourism research published between 1995 and 2013. This search, focused on literature addressing changes in tourists’ environmentally related knowledge, attitudes, intentions, and actual behaviors, yielded just 30 empirical studies. Outcomes related to new environmental knowledge were commonly reported in these studies, but findings related to environmental attitudes and behaviors were inconsistent. Few studies measured environmental behavior directly, and fewer still include longitudinal assessments of persistent changes in attitudes or behaviors. We suggest potential future areas for research as well as programmatic strategies that may facilitate favorable outcomes from nature-based tourism, particularly those related to tourists’ knowledge, attitudes, and behaviors. Key areas include understanding visitors’ prior experiences and background, designing and delivering more effective interpretive messages, and using social media. [ABSTRACT FROM PUBLISHER]