Purpose: Sustainable regional development is often accompanied by the introduction and gradual implementation of innovative concepts, like, e.g. "integrated natural resources management" or "sustainable tourism". From a managerial perspective, in order to contribute to improved sustainable regional development, the innovative concepts need to become rooted in everyday policy practice in such a way that they enable rather than hinder collective action. The paper aims to discuss these issues. Design/methodology/approach: Enabling collective action is a managerial challenge that is partly dependent on the presence of a sufficient degree of integration in the governance system that forms a context for the action. This challenge can be studied with the help of the concept of boundary judgments. Boundary judgments are normative and cognitive perceptions of actors on the relevancy of specific actors, factors, issues, etc. for their domain of action (what is "fit", what is acceptable, what is needed?). The paper illustrates the importance of boundary judgments through two empirical studies in The Netherlands. Findings: Divergent boundary judgments hamper the inclusion of the innovative concept in everyday actions for improving sustainable regional development. However, managers avoiding this complexity by relying on old definitions of their tasks also block the possible innovation. The challenge is to keep the balance between these two extremes. Originality/value: The paper explains and illustrates the concept of "boundary judgments" and their importance for different types of managers (project leaders and policy makers) to take them into account, alongside the more obvious variation of values and interests among stakeholders.