This randomized controlled study involved 236 1b genotype (121 males) naive patients with chronic hepatitis C. After a course of interferon (IFN)-alpha2b plus ribavirin for 6 or 12 months, 117 (49.5%) of the end-therapy responders were equally divided into two groups and were assigned to receive either low daily doses of IFN-alpha2b (1.5 MU) 'consolidation therapy' (59 patients) for 1 year or no further treatment (58 patients). At the end of the follow-up period (6 months), the number of sustained responders in the consolidation group (83%) was significantly higher than in the control group (37.9%). The predicting factors of both end-therapy response and sustained response were the classic ones and a lower GGT/ALT ratio (GGT: gamma-glutamyl transpeptidase; ALT: alanine aminotransferase). The strongest predictors of sustained response alone were consolidation therapy and the longer period on combined treatment (12 vs 6 months). Consolidation therapy was better tolerated than the previously prescribed combined therapy in terms of side effects. In conclusion, genotype 1b naive end-therapy responders to usual combined therapy, after a period of daily consolidation therapy with a low dosage of IFN without ribavirin, achieved a better rate of sustained response than the control group.