Patients with chronic hepatitis C infected with HCV genotype 2 and 3 can be successfully treated in more than 80 % of cases. It had been shown that a 24 week t.i.w. treatment period with standard interferon alpha and ribavirin is sufficient for these patients. However, the recent multicenter studies investigating the effect of pegylated interferons and ribavirin used a 48 week schedule for all patients irrespective of the HCV genotype. Thus, we prospectively investigated the efficacy of a 24 week treatment period with pegylated interferon alpha-2b (1.0-1.5 microg/kg o.i.w.) and ribavirin (1-1.2 g daily) in 54 patients with HCV-genotype 2 and 3 at two different sites. 29 patients were included in Herne (private practice) and 25 patients were treated in Hannover (Medical School). After the end of follow-up 46 (85%) patients showed a virological sustained response in the intent to treat analysis. Only four patients demonstrated a virological treatment failure (3 relapse, 1 breakthrough), two patients were non-compliant, and at each center therapy was stopped in one patient due to adverse events. There was no difference regarding treatment response between both sites, even though the patients in Herne were treated only with 1,0 microg/kg PEG-IFN alpha-2b, while patients in Hannover received 1,5 microg/kg PEG-IFN alpha-2b. In conclusion, the response rates of this study do not differ from the results of the 48 week treatment period of the recently published multicentre trials. Thus, we suggest treating all patients with HCV-genotype 2 and 3 for only 24 weeks when PEG-IFN alpha-2b is used in combination with ribavirin.