SUMMARY
This study describes and analysis five years of experiences from organising an interorganisational project on vocational rehabilitation. A qualitative case study approach was used based on interviews, focus group discussions and documents. The aim was to analyse how and why the project was organised in the way it was in relation to theories of integration, organisational change and learning. The results show that the vocational rehabilitation project was initiated mainly for financial reasons. It was organised as a mechanistic system with the aim of producing different activities, where financial control and support from all the levels of the organisations involved was important. A new bureaucracy between the different authorities involved was built up, where the vertical (top‐down) integration was more important than the horizontal. The result was scattered islands of interprofessional work in different teams, but without contacts between them. The project did not influence the processes or workflows of the organisations involved in the project, which would be important from a service‐user perspective. It may therefore be questionnable to organise the development of interorganisational integration for vocational rehabilitation in a separate project organisation. Instead, interorganisational networks with focus on interconnections of processes and workflows may be more flexible and adaptable. Copyright © 2010 John Wiley & Sons, Ltd.