This article reports on a European project that sought to explore the relationships between social work and service user participation, using a five-country (Belgium, Czech Republic, Finland, Ireland and Portugal) case study approach. It revealed areas of comparison and contrast depending upon respective histories of social work development, organisation, education and research that determined forms of service user participation. It is argued that such cross-national case study approaches can enhance our understanding of vital aspects of social work organisation, practice, education and research in the social work research, policy and practice community in areas of service user participation.