This study sought to explore teachers' perceptions of new principals (NPs) and how these perceptions influenced different aspects of their work environment. The research was conducted using case study methodology of three schools in Melbourne, Australia. Data collection tools included semi-structured interviews of teachers and principals, supported by non-participant observations and the study of school documents. The results showed that teachers' perceptions of their NP were a function of the incomer's personal and leadership qualities and practices, which, in turn, were informed by three contextual factors: school leadership history, the origin and background of the NP, and teacher expectations. These perceptions appeared to influence several domains within teachers' work environment, mainly teacher morale and, to a lesser extent, teacher professional development. A new conceptual model for understanding teachers' perceptions of an NP has been distilled from the data.