This study explores (a) what Greek school principals value as important both for themselves as principals (desired values) and for other principals in school administration (desirable values), directly and indirectly; and the Greek school principals opinions (b) about the factors affecting their personal and professional values and (c) about the importance of values in educational administration. Twelve principals were invited to decide upon vignettes (hypothetical scenarios) for their values indirectly to be unraveled, whereas semi-structured interviews were applied for the participants‟ values directly to be investigated and the other two research questions to be answered. The data were analyzed with the qualitative content analysis. A consistent finding emerged between the principals‟ desired and desirable values, explored both directly and indirectly, was the prevalence of the values of consequences for immediate clients (students, educators and parents) and collaboration. Regarding the factors impacting on principals‟ personal values, family, friends, and the Christian religion were mentioned as highly influential, while the principals‟ professional values were shaped mostly through their professional experience and their career path in Greek educational administration. However, interestingly, the principals‟ immediate supervisors seemed to affect mainly negatively the participants‟ professional values. These findings were found to reinforce and extend the research indicating the significance of values in educational administration, and they are discussed in terms of their implications for value-led principalship and principals‟ professional development