Any physiopathological hypothesis of HCV infection must explain at least some of the most characteristic features of this infection, namely : 1) persistent infection in the majority of exposed individuals, associated with a wide spectrum of histological damages and fluctuating biochemical expression; 2) low tendency towards spontaneous recovery; 3) high tendency to progress to cirrhosis; 4) high prevalence of autoimmune phenomenons; 5) very weak or absent immunity to reinfection. A model is given taking into account the nature of the HCV genome, the immune response of the host to the infection and the potential mechanism(s) involved in viral persistence.