Migrants living in the European Union/European Economic Area (EU/EEA), in particular those in precarious and insecure situations including those with irregular status, are specifically vulnerable to HIV. Currently, the number of undocumented people is estimated between 3.9 and 4.8 million in the EU/EEA (PEW Research Center, 2019). In recent years, both a shift in migration patterns and reduction in the number of new HIV diagnoses among migrants in the EU/EEA has been observed. However, 42% of all new diagnoses reported in 2018 were still reported among migrants, with 18% among migrants originating from sub-Saharan Africa (ECDC, 2019a). Given that migration will remain a reality for the years to come, there is a critical need to strengthen the evidence-base for a better understanding of the current HIV burden and access to services for vulnerable migrant groups to inform evidence-based interventions. This systematic search and review synthesizes the available evidence based on peer-reviewed and grey literature to answer three review questions: 1) Do migrants living in precarious and insecure situations in the EU/EEA have a higher HIV burden (i.e. HIV prevalence, new HIV infections, and post-migration HIV acquisition) than nationals? 2) Do migrants living in precarious and insecure situations in the EU/EEA have less access to HIV prevention, testing, treatment and support services than nationals? 3) What are the multi-level barriers and facilitators in accessing these services? Based on the available evidence, and using a social ecology lens, gaps in the literature are identified and recommendations can be given to improve access to HIV services for migrants in precarious and insecure situations living in the EU/EEA to and reduce their HIV burden.