Trust is a critical factor in determining whether principal-teacher working relationships are positive or negative. This article begins to explore the concept of trust and its development in twelve Canadian secondary schools that experienced frequent principal turnover in a period of eight years. The authors found that the development of trust between principals and teachers could be described as a four phase continuum that begins at the time of a principal's entry. Perceived ability (knowledge, skills, competence and consistency), the degree to which interpersonal relations develop, and the rate of principal turnover influence whether trust between principals and teachers progresses along the continuum or becomes stalled. The four types of trust along this continuum are Role, Practice, Integrative and Correlative. (Contains 1 table and 1 footnote.)