BackgroundWhile the public health benefits of new HCV treatments depend on treatment adherence, particularly among people who inject drugs (PWID), several social and medical factors can jeopardize treatment adherence. The aim of this study is to examine the qualitative literature on facilitators to HCV treatment adherence among PWID.MethodsWe searched six databases to identify qualitative research studies on HCV treatment adherence facilitators among PWID. Two reviewers independently extracted and analyzed data using PRISMA guidelines and the CASP tool to evaluate study quality.ResultsFrom ten studies representing data from 525 participants, three major themes emerged across studies: logistical facilitators within health systems enhanced HCV treatment adherence, positive social interactions between PWID and staff provided positive feedback during treatment, and HCV treatment may complicate the addiction recovery process.ConclusionsAlthough PWID face several barriers to adherence, we identified treatment adherence facilitators that could be incorporated into clinical practice.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-016-3671-z) contains supplementary material, which is available to authorized users.