Purpose: There is a growing call for novel approaches in education with respect to sustainable development. Transformative learning lacks empirical research. This paper responds to that gap and aims at analysing how transformative learning nurtures ecological thinking. Design/methodology/approach: The "Students Swap Stuff" sustainability project is the result of a transformative and action-oriented learning process within the course Corporate Social Responsibility of the Master Environmental, Health and Safety Management, Faculty of Economics and Business at KU Leuven, Brussels, Belgium. Framed by the appreciative inquiry method, students set up a swapping system to limit overconsumption, waste and spillage caused by students' stay in Brussels for a semester or longer. The paper is focusing on participatory action research, using semi-structured interviews with twenty-two participating students exploring whether their assumptions regarding the dominant paradigms in management have been transformed. Forty-nine participants in the closet swap completed a questionnaire related to their motivations. Findings: The project was helpful in rethinking the traditional economic system and in decentering the economic element allowing for a different way of thinking, integrating trust and restoring the value of just giving. Four insights from the Students Swap Stuff project are relevant for other action-oriented learning approaches: start from a specific framework to guide the action; give enough time to dream what might be, but always link it to delivering what will be; insert sufficient moments of reflection; and give the students ample opportunities to express their feelings during the project. Research limitations/implications: First, the research focused on one case, the Students Swap Stuff, with a limited number of students participating in the project. The aim of action-oriented learning, however, was not mere action, but the action had to lead to insights that are helpful for other cases and situations. Second, the interviews were set up between peers. Information about their background, such as families, preferred activities during leisure time, attitudes in favor of the environment, were not directly integrated in the semi-structured questions. This could be part of follow-up research emphasizing aspects of environmental psychology. Practical implications: This study reveals that transformative and action-oriented learning demand a lot from students and lecturers. To avoid confusion on the concept "action," praxis could be used to emphasize that thinking and doing exist simultaneously. Students learn in a natural way, but do not always see the effects immediately. Lecturers have to respond to this in a constructive way and have to include reflection moments on a regular basis. Originality/value: Apart from the dominant research on students as objects, there is little research with students. This paper goes further by combining two stances: students as co-creators of knowledge; and students as participants in action research.