The Alma Ata and Astana Declarations reaffirm the importance of high-quality primary healthcare (PHC), yet the capacity to undertake PHC research-a core element of high-quality PHC-in low-income and middle-income countries (LMIC) is limited. Our aim is to explore the current risks or barriers to primary care research capacity building, identify the ongoing tensions that need to be resolved and offer some solutions, focusing on emerging contexts. This paper arose from a workshop held at the 2019 North American Primary Care Research Group Annual Meeting addressing research capacity building in LMICs. Five case studies (three from Africa, one from South-East Asia and one from South America) illustrate tensions and solutions to strengthening PHC research around the world. Research must be conducted in local contexts and be responsive to the needs of patients, populations and practitioners in the community. The case studies exemplify that research capacity can be strengthened at the micro (practice), meso (institutional) and macro (national policy and international collaboration) levels. Clinicians may lack coverage to enable research time; however, practice-based research is precisely the most relevant for PHC. Increasing research capacity requires local skills, training, investment in infrastructure, and support of local academics and PHC service providers to select, host and manage locally needed research, as well as to disseminate findings to impact local practice and policy. Reliance on funding from high-income countries may limit projects of higher priority in LMIC, and 'brain drain' may reduce available research support; however, we provide recommendations on how to deal with these tensions.