Middle managers, such as school form managers and school area managers, have come to play a crucial role in local public administration in Sweden. We need to understand the forms of power they exercise, as middle managers – in contrast to chief education officers and principals – they do not have a legally defined mandate. This article draws upon new institutionalist perspectives to enhance knowledge and understanding of how chief education officers, middle managers, and principals perceive middle managers to exercise power over, power to, and power with in administrations and in relation to other officers. Semi-structured interviews were conducted with respondents in four local education administrations across three municipalities in Sweden. The results show that middle managers in the study exercise all three types of power, and that not only regulative but also normative and cultural-cognitive perspectives contribute to explaining the expansion or limitation of their power. Notably, the institutional perspectives can coexist to different degrees, depending on the context and situation, with implications for the relative administrative power of middle managers. Without a clearly defined legal mandate, their exercise of power raises urgent accountability concerns.