The objective of this paper is to show the way in which trust within a teaching staff translates into mutual learning among teachers. Using a qualitative investigation of two purposively selected schools representing a high and a low level of trust within the teaching staff, we illustrate that trust is a multi-layered phenomenon which in the context of learning among teachers is not necessarily productive to work with as a whole. We therefore separate trust within a teaching staff into the head teacher's trust in teachers, teachers' trust in the head teacher, overall trust among teachers, and finally trust between specific teachers in a learning relationship. We relate these levels of trust within a teaching staff and the three components of this trust—competencies, relationships, and reliability—to the characteristics of mutual learning among the teachers at the selected schools. We conclude that our data shows that the key relationship influencing learning among teachers is that between the head teacher's trust and trust in the head teacher, which has the greatest impact on whether teachers accept the head teacher's concept of professional development and act accordingly. Overall trust among teachers has an influence on the level of independence of learning interactions and awareness of colleagues' learning but not on shared learning content.