To describe leadership as ethical is largely a perceptional phenomenon informed by beliefs about what is normatively appropriate. Yet there is a remarkable scarcity in the leadership literature regarding how to define what is "normatively appropriate." To shed light on this issue, we draw upon Relational Models Theory (Fiske, 1992, Psychol Rev, 99:689-723), which differentiates between four types of relationships: communal sharing, authority ranking, equality matching, and market pricing. We describe how each of these relationship models dictates a distinct set (...) of normatively appropriate behaviors. We argue that perceptions of unethical leadership behavior result from one of three situations: (a) a mismatch between leader's and follower's relational models, (b) a different understanding about the behavioral expression, or preos, of the same relational model, or (c) a violation of a previously agreed upon relational model. Further, we argue that the type of relational model mismatch impacts the perceived severity of a transgression. Finally, we discuss the implications of our model with regard to understanding, managing, and regulating ethical leadership failures. (shrink)