To determine the sustained virological and biochemical response rates and and the factors infuencing them in hepatitis C patients on interferon+ribavirin combination therapy, 73 therapy naive hepatitis C patients who received interferon (IFN) alpha 2a or 2b (3x3 Mu/w or 3x4.5-5 MU/w) in combination with ribavirin (RIB) (800-1200 mg/qd) for one year were fallowed up. Therapy was stoped in patients who were still HCV RNA pozitif at the sixth month. Ninety seven percent (34/35) of the patients were genotype Ib. Fifty nine percent of the patients were HCV negative at the third month, 66% were negative at sixth month and 61% at one year. Six months after cessation of therapy, virological and biochemical response rates were 53% and 52% respectively. There was no correlatian between the response rates and the type and the dose of the IFN, the alanine aminotransferase levels (ALT) and fibrosis score before the therapy, age and gender (p>0.05 for all). Histological responses were concordant with virological and biochemical responses. Our results indicate that standard IFN alfa+ribavirin combination therapy induces sustained virological and biochemical response in more than half of the chronic hepatitis C patients independent of age, gender, type and dose of IFN, ALT levels and fibrosis score before therapy.