•Telecoupling combined with institutional analysis can make up a diagnostic approach to shed new light on the management of ICDPs.•Flows of information, assets, and rules and regulations between project actors are decisive for the opportunity of collective decision-making.•The direction and directness of information flows provide insights on the degree of institutional distance between project actors.•Management situations where there are no or few direct and bidirectional flows between project actors can be diagnosed as decoupled. The opportunities and challenges of ensuring participation and success of Integrated Conservation and Development Projects (ICDPs) have been fairly studied. However, it is not often well-established which institutional mechanisms explain the failure in meeting participatory and project goals. To fill this gap, we develop a telecoupling-inspired diagnostic approach to assess the level of institutional distance and opportunity for collective decision-making in ICDPs by looking at project information flows, project asset flows, and rules and regulation flows between project actors. We construct three management archetypes based on the direction and directness of such flows: decoupled management, telecoupled management and collaborative management. The archetypes are applied to a case study of a World Bank-financed ICDP in Argentina, drawing on qualitative data collected from individual interviews with project actors. Our findings challenge the notion that a project becomes participatory if the project design provides guidelines for participatory implementation. We find that our diagnostic approach helps to concretize the call for inclusion of local project actors across the project cycle, which is needed to make projects collaborative, relevant, and socially just. Finally, we advocate future project assessments to build on this approach and map the practical institutional relationships between project actors to provide transparency on the de facto level of project collaboration. This article is relevant for both academics and practitioners designing and implementing conservation and development projects.