The advent of interferon-free direct-acting antiviral therapy for hepatitis C virus (HCV) infection has heightened discussion of treatment as prevention. Rapid scale-up in many settings, and the prospect of further treatment simplification have extended therapeutic optimism towards HCV elimination. However, questions remain regarding the feasability of HCV treatment as prevention, including real world efficacy of direct-acting antiviral therapy, particularly among people who inject drugs, and whether expanded treatment access will be sufficient to reduce HCV transmission. HCV re-infection among both people who inject drugs and HIV-infected men who have sex with men might also compromise the benefits of HCV treatment as prevention. Empirical studies of HCV treatment as prevention are ongoing, including among community-based people who inject drugs, prisoners, and HIV-infected individuals. Some national HCV elimination programmes have also been established. Key requirements to optimise benefits of HCV treatment as prevention will include enhanced HCV diagnosis and linkage to care, high-coverage harm reduction, drug price reform, and removal of liver disease and drug use-based restrictions to treatment access.