While ecotourism principles emphasize the importance of educating tourists on nature conservation, a significant knowledge gap persists regarding the effectiveness of eco-labelling for promoting conservation education and meeting ecotourists’ educational expectations. This study addresses this gap using mixed methods, examining perspectives from both the demand and supply sides. To understand tourists’ viewpoints, an empirical study evaluates how interpretation services during guided ecotours align with tourists’ nature conservation learning needs. Additionally, in-depth interviews with guides explore their interpretative performances and whether they prioritise an educational role in fostering tourists’ eco-friendly behaviours onsite. The integrated findings underscore a disparity between tourists’ expectations for their learning needs and guides’ interpretive service performance. Specifically, guides perceive shaping ecotourists’ pro-nature conservation behaviours as a complementary role, resulting in their interpretation services having a limited impact on encouraging responsible actions. Notably, results suggest that guides’ interpretative performance could significantly foster tourists’ conservation support and learning by using guiding tactics to evoke emotional empathy, promote positive emotions, and establish a connection to educational experiences. This study offers significant theoretical insights into ecotourism guide roles, interpretation dynamics, and pro-nature conservation behaviours, while proposing strategic implications to improve interpretation services, educational experiences, and sustainable ecotourism practices.