INTRODUCTION Understanding primary care access or health service utilisation challenges among immigrant communities is important for tailoring services to community needs, which is the core of precision population health. AIM We aim to inventory the primary care access barriers faced by immigrant communities through a comprehensive systematic review and develop a conceptual framework to explain the barriers, using a root cause analysis approach. METHODS Academic databases of primary research articles and grey literature will be searched using appropriate keywords. Relevant information will be extracted into tabular format from finally selected literature. Our proposed approach of framing the barriers to identify the root causes is adapted from the root cause analysis method, which is the process of identifying and understanding the underlying causes to discover the root causes of problems. RESULTS The study will produce a systematic, quantified and documented list of the barriers faced by immigrants in a solution-oriented approach. DISCUSSION The proposed research, as a first step towards determining possible mitigation strategies for health-care access by immigrants, will provide the background needed to devise and test tailored interventions to improve future access to health care for immigrants. We will follow the integrated knowledge translation or community engagement knowledge mobilization approach, where we are engaged with community-based citizen researchers from the inception of our programme. We plan to disseminate the results of our review through meetings with key stakeholders and social media outreach, followed by journal publications and presentations on relevant platforms.