Background It is internationally accepted that in drug-nave individuals with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection, chronic hepatitis C should be treated first if the CD4 cell count does not require the initiation of anti-retroviral therapy. Present paper evaluated the clinical effect and side-effect of interferon-α (IFN-α) and ribavirin (RBV) combination therapy for Chinese patients with HCV-HIV co-infection, and compared with them for HIV infection alone. Methods Ten patients with HCV-HIV and 17 patients with HCV received 5 million unit IFNα-2b every other day intramuscularly, and 300 mg RBV triple daily by oral. Dynamic observations were made for HCV RNA and HIV RNA loads, CD4+ and CD8+ T lymphocyte counts, liver function and blood cell measurement, and the medicine side-effects. Results After 12-week and 24-week treatments of IFN-α and RBV combination therapy, mean HCV RNA levels reduced 1.14 logs and 1.56 logs from the baseline at week 0 in HCV-HIV co-infection, and reduced 1.48 logs and 1.75 logs in HCV infection, respectively. The HIV RNA levels decreased 1.22 logs and 1.32 logs from the base line; however, there were no obvious different changes at T lymphocyte counts of HCV-HIV and HCV patients through 24-week treatments. Whole 27 patients showed satisfactory biochemical response to therapy. There were some mild or mediate influence-like symptoms, intestinal uncomfortable and depressed blood cell counts in early stage of the treatments. No neuropsychiatric and auto-immune disorders were found. Conclusions IFN-α and RBV combination therapy had similar anti-HCV effects during 24-week treatment for HCV-HIV and HCV infected Chinese patients, and some anti-HIV effect. There were no obvious different biochemical responses and side-effects between two groups above.