Purpose: This paper aims to investigate the educational benefits and challenges of introducing natural science students to on-campus and off-campus sustainability research projects as an approach to education for sustainability. Design/methodology/approach: The course "Science and Sustainability" at the University of Leuven is a stand-alone course that aims at providing master students in the natural sciences, education for (the benefit of) sustainability action. It was launched in 2016-2017 and has been running for two years now. The first year focused on getting students acquire a similar level of knowledge in sustainability, while, on a higher level, the experiential learning phase (project work) was supported with specific reflection assignments. In the second year, more specific attention was directed toward allowing students to get acquainted with systems thinking and deal with inter- and transdisciplinary issues by approaching problems from a multi-stakeholder view. Insight in the impact and the appreciation of the setup of the course was obtained from a series of questionnaires offered to all participating students at the beginning, about midway, and again at the end of the course. Findings: Analysis of the students' self-reported sustainability competence development shows a clear positive impact for almost all students who participated. A clear relation between the observed change and the students' self-rating and attitude at the start, as well as with their discipline, is observed. Originality/value: Information is gained on a number of factors of importance to impact the students' attitude toward action for sustainability, and how this can be further improved.