Illicit drug users are the primary risk group for HCV transmission, and will form the largest HCV treatment population for years to come. Sylvestre et al. 's study suggests that cannabis use may benefit treatment retention and outcomes in illicit drug users undergoing HCV treatment. In fact, there is substantial evidence that cannabis use may help address key challenges faced by drug users in HCV treatment (e.g., nausea, depression), especially when such treatment occurs in the context of methadone maintenance treatment which may amplify these consequences. While further research is required on the biological and clinical aspects of the benefits of cannabis use for HCV treatment, and the effectiveness of cannabis use for HCV treatment needs to be explored in larger study populations, we advocate that in the interim existing barriers to cannabis use are removed for drug users undergoing HCV treatment until the conclusive empirical basis for evidence-based guidance is available.