The topic of this paper is to discuss the link – the professional norms – between legal norms and actions regarding education for sustainable development based on an empirical study. The study has a special interest in the role of school leaders and how the implementation of education for sustainable development (ESD) is led, organised and realised. There is also an interest in identifying the kinds of support mechanisms and obstacles to implementation and norm setting exhibited by the school organisations. The theoretical framework follows theories in sociology of law where the relation between law and society is the focus of the research. Education for sustainable development is regulated in the Swedish national curriculum and syllabi, thus constituting legal norms and national goals, which the professionals have to interpret and put into action. The results indicate that professional norms are set when principals and teachers experience expectations from each other, from students and from policy documents. The school principal has a crucial role in these norm setting processes. An expression used by one principal, that they were lacking a “shared umbrella”, is a metaphor for the lack of shared norms to guide ESD.