Studies on hepatitis C virus (HCV) monoinfected patients suggest high sustained treatment response rates of up to 98% when interferon monotherapy is administered during the acute phase of HCV-infection. To clarify whether early treatment of acute hepatitis C is similarly efficient in human immunodeficiency virus (HIV) positive patients, we conducted a retrospective survey of HIV-positive patients with acute HCV infection. Eleven HIV-positive patients who had been treated with interferon or interferon/ribavirin were identified at eight HIV-specialty outpatient clinics. The patients had been treated over a median 25 weeks with standard interferon (two patients), pegylated interferon (four patients) and pegylated interferon in combination with ribavirin (five patients). A post-treatment response (negative serum HCV-RNA at the end of treatment) was seen in 10 of 11 patients and HCV-RNA remained undetectable 24 weeks after the end of treatment in all the 10 responders. Alanine aminotransferase (ALT) normalized in eight patients while two virological responders and one nonresponder showed persistent mild ALT elevations. In conclusion, early treatment of acute hepatitis C seems to achieve high sustained virological treatment response rates also in patients with HIV-infection.