This article describes an example of inter-professional action research conducted by teachers and university-based researchers/teacher educators in a vocational college in the Netherlands. The research was aimed at the professional learning of the teachers on their pedagogical approach to a new curriculum initiative. Despite a difficult context in the Netherlands for a type of action research in which teachers and researchers work in democratic collaboration on the improvement of teaching practices, this inter-professional collaboration worked out well. The participants worked, inspired by shared commitment towards the students, as equal partners. In the findings and conclusion insights developed about key elements for inter-professional collaborative research, such as the importance of common relevance, shared responsibility for the research and mutual trust and respect for differences in professional identities and working conditions are addressed.