The active involvement of people with intellectual disabilities (ID) in research is expected to lead to relevant research outcomes, increased quality of life, improved healthcare, reduction of health inequities, and empowerment of people with ID. Despite the developments in inclusive health research, a lack of transparency remains with regard to how the partnership between researchers with and without ID is shaped and structural study of inclusive health research is needed. This study aims to gain insight into the experiences of inclusive research teams in practice regarding (1) reasons, (2) attributes, and (3) outcomes of inclusive health research. A structural study of four inclusive research teams was conducted in Ireland, Northern Ireland, and the Netherlands using case study methodology. Data were triangulated through documents and individual and group interviews. Data were analyzed and synthesized using domain and taxonomic analysis. Reasons for conducting inclusive research ranged from personal to practical. Having an inclusive ethos was found to be crucial in conducting inclusive research meaningfully in practice. Based on data analysis, attributes of inclusive research consist of three interrelated themes, one focusing on methodological aspects and two focusing on active involvement and partnerships. Outcomes of inclusive research across cases were found within three categories relating to research practice, inclusion itself, and interpersonal outcomes. Empowerment was found to be important. Although empowerment is not new to inclusive research, its positive effect on research quality appears to be new and needs further research. This study’s results and the literature indicate that developing inclusive research policy and practice requires a realistic perspective, with a balance between maximum collaboration and using researchers’ strengths. The results of this study are transferrable to inclusive research using similar methods with other groups. When the aim is to share learning in groups, a shared language is needed.