PurposeThe aim of this article is to study the coordination of comprehensive services for clients with concurrent substance abuse and mental health disorders (dual diagnosis), which is a very complex client group. In order to achieve comprehensive care and treatment, the service providers need to cooperate and coordinate, but the questions here, are how this is done and how appropriate the coordination is.Data and methodsData were collected from group interviews during a 1-day workshop with clients, relatives, and employees from the various services involved.ResultsInformation exchange between the services was generally in writing. Coordination between substance abuse and mental health services was experienced as fragmented. Employees had an unclear perception of the work and expertise of the other service providers involved. There were examples of disparity between the services a municipality could offer and client needs. A coordinator, if available, was emphasized by both clients and service providers as serving an important function in coordination and relationship building.ConclusionPredominantly written communication and unclear division of responsibilities and duties resulted in employees creating stereotypes of each other, both within specialist health services and between specialist and municipal health services. A coordinator was able to coordinate various inputs, often through informal contact, with a view to establishing appropriate services for individual clients. Coordination in interagency meeting points, such as “responsibility teams”, was the most successful solution, but this will involve a greater degree of networking than is common today.