The need to identify and suitably prepare teachers to undertake school leadership roles especially as principals is now well documented in the literature. Similarly documented is the general concern about the lack of suitable applicants willing to consider the role. This study raised the question of what might be learnt when a purposefully-selected cohort of 31 teachers drawn from executive, non-principal roles participated in a year-long, multi-phased leadership development program: The Flagship Program of the Association of Independent Schools of New South Wales, Australia (AIS). The design of the program was informed by internationally acknowledged principles of good practice in leadership preparation. Evaluation of the program combined action learning methodologies working with participants with more formal evaluation of each of the program’s stages to investigate participant growth and program effectiveness. The action learning component undertaken with the direct involvement of all participants and with the support of the Australian Institute for Teaching and School Leadership (AITSL) was able to pinpoint what the participants themselves saw as important and what was less so at this stage of their preparation for school leadership roles. In so doing, the study adds a valuable participant perspective to the overall literature on leadership preparation.