In the past 10 years, progress has been made in the management of patients with chronic hepatitis C. A sustained virological response (SVR) is achieved in 80-85% of patients infected with hepatitis C virus (HCV) genotype 2 or 3 after 24 weeks of treatment with peginterferon-alpha and ribavirin. Treatment durations <24 weeks have been investigated to determine whether shorter-term therapy reduces adverse effects and costs compared with longer-term therapy without compromising efficacy. Three studies involving only patients with HCV genotype 2 or 3, with different baseline patient characteristics have shown that 12-16 weeks of treatment can be as effective as 24 weeks of treatment. In all three trials, undetectable HCV RNA 4 weeks after the start of treatment was defined as rapid virological response (RVR), and only patients with RVR stopped treatment early. In the first trial, 75% of patients treated with peginterferon-alpha-2b and ribavirin achieved RVR; these rapid responders achieved an SVR rate of 90% after 14 weeks of treatment. In the second trial, 63% of patients achieved RVR after 4 weeks of treatment with peginterferon-alpha-2b and ribavirin, and 85% of patients with RVR achieved SVR after 12 weeks of treatment. In comparison, 91% of patients with RVR treated for 24 weeks had SVR. In the third study, 93% of the total study population achieved RVR and were randomly assigned to 16 or 24 weeks of treatment with peginterferon-alpha-2a and ribavirin. Among patients with RVR, 85% in the group treated for 16 weeks and 80% in the group treated for 24 weeks achieved SVR. Among patients with HCV genotype 2 or 3, achieving an RVR to interferon-based treatment is common and a criterion to reduce the duration of treatment. In patients with genotype 2 and RVR, 12 weeks of therapy with peginterferon-alpha and ribavirin is recommended. For patients with genotype 3, a univocal recommendation on treatment duration cannot be made. However, ongoing trials will probably clarify this aspect.