OBJECTIVES: To assess the evidence of differences in the risk of HIV, sexually transmitted infections (STI) and health-related behaviours between migrant and non-migrant female sex workers (FSWs). METHODS: Systematic review of published peer-reviewed articles that reported data on HIV, STIs or health-related harms among migrant compared with non-migrant FSWs. Studies were mapped to describe their methods and focus, with a narrative synthesis undertaken to describe the differences in outcomes by migration status overall and stratified by country of origin. Unadjusted ORs are presented graphically to describe differences in HIV and acute STIs among FSWs by migration and income of destination country. RESULTS: In general, migrant FSWs working in lower-income countries are more at risk of HIV than non-migrants, but migrants working in higher-income countries are at less risk. HIV prevalence was higher among migrant FSWs from Africa in high-income countries. Migrant FSWs in all countries are at an increased risk of acute STIs. Study designs, definitions of FSWs and recruitment methods are diverse. Behavioural data focussed on sexual risks. DISCUSSION: The lack of consistent differences in risk between migrants and non-migrants highlights the importance of the local context in mediating risk among migrant FSWs. The higher prevalence of HIV among some FSWs originating from African countries is likely to be due to infection at home where HIV prevalence is high. There is a need for ongoing monitoring and research to understand the nature of risk among migrants, how it differs from that of local FSWs and changes over time to inform the delivery of services.