An acute hepatitis C infection was diagnosed in three HIV-positive gay men, aged 43, 48 and 30 years, respectively. In all three, unprotected sexual intercourse and fisting was a universal risk factor for the infection. They all denied having used drugs intravenously, which is the most common risk factor. The third man had a documented proctitis (lymphogranuloma venereum) at the time when the HCV transmission must have taken place. No serious complications occurred during the acute HCV infection. Because the infection did not resolve spontaneously after a few months, all three men were treated with pegylated interferon and ribavirin. Recently, the number of cases of acute HCV infection has been seen to increase in The Netherlands. This may be due primarily to an increase in unprotected sexual intercourse and fisting. This hypothesis is supported by a documented increased prevalence of sexually transmissible diseases among gay men in The Netherlands. As acute infections may turn into chronic infections, treatment of an acute infection should be considered in order to prevent the chronic disease.