School principals and teachers are expected to continuously innovate their practices in changing school environments. These innovation processes can be shared more widely through collaboration between principals and teachers, i.e. "collaborative innovation." In order to gain more insight into how school principals enact their leadership practices in leading collaborative innovation, we interviewed 22 school principals of primary, secondary and vocational education in the Netherlands. All participants have implemented the same collaborative innovation programme, aimed at enhancement of collaboration between teachers and school principals within schools, that has already been implemented by 900 Dutch schools. They were interviewed twice during the implementation year. Interview transcripts were analysed using an open coding strategy looking for leadership practices. Based on 11 leadership practices, we described two main leadership patterns: school principals enacting leadership practices as either a "team player" or as a "facilitator." We conclude that our findings suggest a wider repertoire of leadership practices than is reported in previous studies. Future studies would need to address the generalisability of the practices and patterns as found in this specific context of collaborative innovation.