: BACKGROUND: We investigated the association between actual and self-reported hepatitis C virus (HCV) status and alcohol consumption among injecting drug users (IDUs) to determine whether IDUs who self-report as HCV infected comply with UK guidelines on safe drinking and to determine risk factors for drinking. METHODS: We conducted a repeat cross-sectional survey of IDUs accessing harm reduction services in Glasgow in 2005 and 2007. We measured self-reported weekly alcohol consumption, excess drinking (defined as exceeding the UK Royal College of Physician's guidelines for safe drinking of 14units/week for women and 21units/week for men) and HCV antibodies (anonymously in oral fluid). RESULTS: Among IDUs who tested HCV antibody positive, 65% drank alcohol and 29% drank to excess, compared to 61% (p=0.3) and 18% (p<0.001) of those who tested negative, respectively. IDUs who self-reported as HCV positive were less likely to drink but as likely to drink to excess as self-reported negatives or those with HCV status unknown, both among all IDUs and those who tested HCV antibody positive. Among the antibody positives, excess drinking was associated with incarceration (aOR=2.56; 95% CI: 1.28-5.12), homelessness within six months of interview (aOR=3.60; 95% CI: 2.00-6.48) and homelessness more than six months before interview (aOR=1.93; 95% CI: 1.06-3.53). CONCLUSIONS: IDUs who believe they are HCV infected are more likely to abstain from alcohol, but those who drink continue to do so to excess. IDUs diagnosed with HCV need greater support to reduce their alcohol consumption.