This paper explores the concept of ethos as a facet of the government's rapidly growing initiative of the "specialist school". Schools accepted on to the scheme are expected to create a new identity, or ethos: but what exactly is meant by that rather nebulous term? And, in reality, is something as all-consuming as a school ethos, or culture, something that a school can readily conjure up? This discussion, one facet of the author's case study of a Specialist Sports College, explores the concept of school cultures, but also gives consideration to areas such as conflicting and "toxic" cultures, and to the possibility that changing a school's culture can have negative as well as positive effects.