Infection with the Hepatitis C virus (HCV) has been aetiologically linked with the lymphoproliferative disorder mixed cryoglobulinaemia and more recently with certain subgroups of B cell non-Hodgkin's lymphoma (NHL). Many of the studies which have documented the association with NHL have originated from Italy, where the background prevalence of infection with the virus is relatively high. We have performed a study, based in the West of Scotland, to determine the prevalence of infection with HCV in an unselected group of 110 individuals with lymphoproliferative disorders (72 with NHL, and 38 with chronic lymphocytic leukaemia). None of our cohort (both NHL and CLL) had evidence of infection with the virus. Our study suggests that whilst HCV may be important in the aetiology of certain subgroups of NHL, this effect may be regional and dependent upon the background prevalence of the virus in the community.