Amongst people on opioid maintenance treatment (OMT), chronic hepatitis C (HCV) is common but infrequently treated. Numerous barriers, including misuse of alcohol may limit efforts at anti-viral treatment. The aim of this study was to define barriers, including alcohol misuse, to the effective treatment of HCV amongst OMT recipients. Ninety-four OMT patients completed the 3-item Alcohol Use Disorders Identification Test (AUDIT-C). A semi-structured interview was used in 53 subjects to assess alcohol use in detail, psychological health, discrimination and access to HCV treatment. Feasibility of brief intervention for alcohol misuse was assessed. Of the screening participants, 73% reported they were HCV positive. Of the detailed interview participants, 26% reported no drinking in the past month, but 53% scored 8 or more on AUDIT and 42% exceeded NHMRC drinking guidelines. Twenty subjects received brief intervention and among 17 re-interviewed at one month, alcohol consumption fell by 3.1 g/day (p = 0.003). Severe or extremely severe depression, stress and anxiety were found in 57%, 51% and 40% of interviewees respectively. Episodic heavy drinking, mental health problems, perceived discrimination, limited knowledge concerning HCV were all common and uptake of HCV treatment was poor. Brief intervention for alcohol use problems was acceptable to OMT patients, and warrants further study.