Purpose: This paper aims to explore the outputs of an internship programme, one of a number of campus-based sustainability activities that have been introduced at the University of Wales, Trinity Saint David, to encourage student-led campus-based greening initiatives. Design/methodology/approach: A case study approach was undertaken, allowing the researcher to investigate the programme in its real-life context. The researcher used multiple sources of evidence to gain as holistic a picture as possible. Findings: Interns report positive changes in their behaviours towards sustainability, as well as encouraging feedback on their experiential learning, the development of their soft skills and the creation of new knowledge. Moreover, students communicated perceived benefits for their future careers. The reported outcomes reflect mutually beneficial relationships for student and institution, for example, raising the profile of campus greening activities and supporting the University's aim to embed sustainability throughout its campus, community and culture. Research limitations/implications: The researcher recognises the limitations of the research, in particular, the small sample size, which has resulted primarily in qualitative results being presented. Practical implications: Feedback from previous interns will be used to shape future internships. In particular, Institute of Sustainable Practice, Innovation and Resource Effectiveness (INSPIRE) will look for opportunities to work more closely with University operations, departments, faculties and alongside University staff, both academic and support staff. Social implications Following student feedback, INSPIRE will give students opportunities for wider involvement, including an opportunity to propose their own projects to shape future internships that meet the needs of student body on campus. Originality/value: Despite being one case study from one institution, the research highlights the value of such programmes for other institutions.