3ie funded five replication studies on influential impact evaluations of HIV prevention and treatment interventions. Impact evaluations studied included cash transfers, country-level development assistance programs, HIV education programs and approaches to administering antiretroviral therapy. This brief outlines 3ie’s replication approach and provides an example of a replication study on task shifting of antiretroviral treatment. The brief then summarises some of the difficulties and challenges encountered across the five replication studies. Finally, the brief provides some recommendations for donors, policymakers and program implementers on how to advocate for improving replication research and practice.