Introduction: Co-infection with Hepatitis C (HCV) and HIV is common and HIV accelerates hepatic disease progression due to HCV. However, access to HCV treatment is limited and success rates are generally poor. Methods: We conducted a systematic review and meta-analysis to assess HCV treatment outcomes in observational cohorts. Two databases (Medline and EMBASE) were searched using a compound search strategy for cohort studies reporting HCV treatment outcomes (as determined by a sustained virological response, SVR) in HIV-positive patients initiating HCV treatment for the first time. Results: 40 studies were included for review, providing outcomes on 5339 patients from 17 countries. The pooled proportion of patients achieving SVR was 38 . Significantly poorer outcomes were observed for patients infected with HCV genotypes 1 or 4 (pooled SVR 24.5 ), compared to genotypes 2 or 3 (pooled SVR 59.8 ). The pooled proportion of patients who discontinued treatment due to drug toxicities (reported by 33 studies) was low, at 4.3 (3.3-5.3 ). Defaulting from treatment, reported by 33 studies, was also low (5.1 , 3.5-6.6 ), as was on-treatment mortality (35 studies, 0.1 (0-0.2 )). Conclusions: These results, reported under programmatic conditions, are comparable to those reported in randomised clinical trials, and show that although HCV treatment outcomes are generally poor in HIV co-infected patients, those infected with HCV genotypes 2 or 3 have outcomes comparable to HIV-negative patients. ? 2013 Davies et al.