Background: Worldwide, patient and public involvement (PPI) in health research has grown steadily in recent decades. The James Lind Alliance (JLA) is one approach to PPI that brings patients, carers and clinicians together to identify priorities for future research in a Priority Setting Partnership (PSP). Our study aim was to describe the reflections of informal carers of people with dementia on the possibility of participating in the JLA's PSP process, for both themselves and the recipients of their care. In addition, we wanted to explore barriers to and facilitators of their participation. Methods: We conducted four focus groups with 36 carers of people with dementia. Thematic analysis was applied to analyse the data. Results: An overarching theme emerged from the participants' reflections: "Creating empowering teams where all voices are heard". The overarching theme incorporates the participants' suggestions about the importance of equivalence in power, mutual agreement with and understanding of the goals, adequate support, openness about each partner's tasks and the bonds needed between the partners to sustain the enterprise, and expectations of positive outcomes. From the overarching theme, two main themes emerged: "Interaction of human factors, the PSP process and the environment" and "The power of position and knowledge". The overall results indicated that carers are willing to participate in PSP processes and that they thought it important for people with dementia to participate in PSP processes as well, even if some might need extra support to do so. The carers also identified the need for research topics that influence their everyday lives, policy development and healthcare services. Conclusions: Both carers and the people with dementia for whom they care are able to contribute to the PSP process when given sufficient support. The involvement of these groups is important for setting healthcare research agendas, developing research projects that increase awareness and knowledge about their circumstances and improving health professionals', researchers' and policymakers' understanding of and insight into their unique situations.