BACKGROUND: Approximately 1 in 4 of the nearly 2 million individuals in state and federal correctional facilities are infected with hepatitis C virus (HCV). Currently, there are few reports of treatment outcomes of this common infection in this setting. OBJECTIVE: To describe HCV therapy in the incarcerated setting. DESIGN: Retrospective, descriptive observational study. SETTING: Rhode Island Department of Corrections, Cranston, Rhode Island. PATIENTS: 93 inmates with chronic HCV infection. INTERVENTION: Interferon-alpha with ribavirin. MEASUREMENTS: HCV RNA levels 6 months after treatment. RESULTS: Response rates are similar to previously published rates achieved in the community; 63% (50 of 79) of patients achieved viral clearance after 6 months of therapy, and 46% (26 of 57) achieved sustained response 6 months after treatment. CONCLUSION: The incarcerated population (which is disproportionately affected by addiction and psychiatric illness) can be effectively treated for HCV infection with interferon and ribavirin. The correctional setting may provide an opportunity to safely treat patients with these two challenging comorbid conditions.