`titreb –The governance of multi-organisational systems – The example of the health and social services system in Quebec – `/titreb This article looks at the overall coordination of multi-organisational health and social services systems, and examines the specific case of Quebec. Written from the standpoint of organisational science and inspired mainly by Anglo-Saxon research, it analyses the hierarchical and formal “integration” of systems, which is a central principle in many structural reforms. This idea does not appear to have a great deal of support, and this article makes a critical analysis of it. It goes on to highlight some operational mechanisms based on mutual adjustment which serve to ensure the overall coordination of multi-organisational health and social services systems.