Although there is substantial research on the effect of emotions on educational outcomes in the classroom, relatively little is known about how emotion affects learning in informal science contexts. We examined the role of emotion in the context of an informal science learning experience by utilizing a path model to investigate the relationships among emotional arousal, valence, attention, environmental values and learning outcomes. Sixty undergraduate and graduate students participated in one of two treatments consisting of watching an exciting or neutral nature documentary video, reading an associated narrative, and taking a post-test. Our findings suggested that higher emotional arousal, less pleasant feelings about the content, and stronger environmental values led to greater short-term learning outcomes. We discuss our findings in relation to current understandings of emotion and learning in informal science education settings.