Purpose: This paper aims to investigate the impacts of service learning (SL) on teaching sustainability competencies in an undergraduate tourism program at Bamyan University, Afghanistan. This study reports on tourism students' experiences in the SL course which taught five key sustainability competencies (collaboration, values thinking, action-oriented, systems thinking and integrated problem-solving). Design/methodology/approach: This paper assessed students' perceptions of their sustainability competencies gained during the implementation of the course in 2016 and 2017 through focus groups, reflective essays and participant observation. Findings: The results demonstrate how the SL experience led students to self-discovery, strong conceptualizations of sustainability and working relationships with community stakeholders. Originality/value: To the best of the authors' knowledge, this is the first study to assess the impacts of a SL course in Afghanistan. The analysis provides valuable information for developing effective higher education programs, relationships of trust between students and community stakeholders and the empowerment of students to contribute to local solutions which serve a role in stabilization efforts in conflict-affected contexts.