Purpose: This paper aims to compare the learning outcomes of gaming simulation and guided inquiry in sustainability education on plastic waste management. The current study targets the identification of success factors in these teaching approaches. Design/methodology/approach: This study used a quasi-experimental design with undergraduate participants who were randomly assigned to an eight-hour sustainability education class using either gaming simulation or guided inquiry. Pre- and post-tests on students' knowledge, attitudes and intended behavior were conducted, followed by individual interviews to provide more detailed reflections on the teaching approach to which they were assigned. Findings: In terms of knowledge acquisition and behavioral changes, the quantitative results suggested that the pre-/post-test in-group differences were significant in both groups. More importantly, a significant positive attitudinal change was observed in the gaming simulation group only. In the interviews, participants attributed effective knowledge acquisition to active learning element in class, while the characterization of cognitive dissonance triggered in the gaming simulation induced subsequent affective changes. Practical implications: Activities in this program can be applied or modified to accommodate differences in other similar programs. The findings can also provide indicators to designs of similar programs in the future. Originality/value: This paper explores plausible factors (ideology and implementation) that contribute to successful sustainability education programs. Through comparison between gaming simulation and guided inquiry, elements for effective education for sustainable development learning in the pedagogical designs are discussed.