Health research is needed to develop new treatments, diagnostic methods and prevention strategies for many diseases, but resources are limited particularly in low-and middle-income countries (LMICs). Our proposed project involves in-depth engagement with community advisory boards and existing community groups in healthcare research priority setting in Thailand. We will use Wellcome's "Responsive Dialogues" engagement approach, focusing on "under-served" groups, as their voices are seldom heard in healthcare research priority setting. We estimate that we will engage with 6-8 community groups involving 48-80 participants. Our objectives are firstly, to contribute to the health research agenda setting in Thailand for government, non-governmental actors, academia, and others who conduct health research in the next 5 to 10 years. Secondly, we aim to identify ethical and practical issues related to healthcare research priority setting, specifically in relation to involving under-served communities.