Background: Little is known about the effectiveness of interventions aimed at enhancing the social networks of people with intellectual disabilities. This study explores the results of such an intervention. How did the clients with mild to borderline intellectual disabilities and their support workers evaluate the intervention? What did they learn from it? Were there any changes in network characteristics, satisfaction and wishes in relation to networks, participation, loneliness, self-determination or self-esteem? Method: The evaluation of the intervention was explored from several perspectives (i.e. five clients, their six support workers and three trainers), using mixed methods (i.e. interviews and questionnaires). Results: The intervention was positively evaluated by both clients and support workers. Moreover, the analysis revealed the vulnerability of clients and their networks but also the benefits experienced from the intervention, such as decreased loneliness, enhanced social networks, increased awareness, competence, autonomy and increased participation. Conclusion: The indicative level of evidence for the effectiveness of this intervention justifies a larger series of case studies or a larger control trial study.