This study investigates the mediating role of social interactions between the ecotourism attitude and ecotourism participation intention of tourism students in Australia. It also examines the moderating influence of gender and length of career relationship on social interactions. Data analysis results from partial least squares–based structural equation modeling confirm a positive relationship among environmental knowledge, ecotourism attitude, landscape likability, and ecotourism participation intention. Findings also reveal that the mediating influence is further moderated by gender difference but not by the relationship length of the student’s tourism career. These findings have important implications for tourism education providers in designing sustainability-related learning materials.