Using survey results compiled from an extensive study into the ethical decision making of school principals this article analyses the nature and consistency of principals' ethical decision-making processes. Based on the findings, the article argues that even though principals on the whole have well-meaning intentions, by and large, they do not display consistent conceptual knowledge of major ethical theories; they exhibit certain contradictions in their ethical reasoning and they suffer regular conflicts with their own personal and professional values. The article concludes by offering some suggestions for future professional development strategies that may serve to better educate principals on the concepts and processes required for consistent, confident and well-reasoned ethical decision making.