The cellular immune response to hepatitis C virus (HCV) plays a critical role in determining the clearance or persistence of HCV. Moreover, in chronic HCV infection, these responses that are insufficient to eradicate virus completely may cause liver injury. In this study, the memory T cells responses specific to the core protein were measured by interferon-gamma Elispot assay after in vitro stimulation of peripheral blood mononuclear lymphocytes from chronically infected subjects. Ten out of the 22 patients studied (45%) present a core-specific response with a preferential recognition of the N-terminal and central parts. There was no relationship between T cell responses and the parameters of disease evolution as determined by ALT (serum alanine transaminase levels), and histologic hepatic damage (Metavir score A and F), but there was a positive relationship between the presence of a core-specific T cell responses and the viraemia.