Teams of teachers and administrators have become more and more common as a framework for improving responsiveness to the ever more dynamic educational environment. Although teamwork is often expected to broaden the team’s collective knowledge base, consequently improving team effectiveness, research shows that this potential effectiveness is not always reached. The article seeks to explore the concept of collective doubting – the inquiry into routine and habitual perceptions and assumptions – and its importance to the teamwork processes, a topic that has been vastly under-investigated in the educational context. Specifically, we propose that collective doubting in the teamwork process has a dynamic nature, and that the doubting process should be carefully considered in the context of different stages in team development. Our goal is to increase both theoretical and practical knowledge about the process of collective doubt in such a way as to facilitate team effectiveness. We further seek to delineate the internal and external activities in which principals can engage to promote a constructive doubting process in the team context. Implications for principals, as well as for further avenues of research, are suggested.