The daily work of organising in schools both configures and is configured by the nature of schools as complex organisations. However, the organisational complexity of schools is often omitted in normative and analytical accounts of schools as organisations. In this paper, we seek to redress that omission and to bring organisational complexity to the fore in theorising about educational organisations and organising. Using a meta-ethnographic approach, we analyse the literature on organisational complexity and loose coupling. We develop and explain the elements of a perspective on schools as complex, evolving, loosely linked systems (CELLS). Using this perspective, we consider significant aspects of schools from this perspective with the intention of establishing its validity and relevance to organisation theory in education.