The prevalence of hepatitis C infection and possible predisposing factors was assessed in a renal unit. Of 343 patients at our renal dialysis centre, 37 (10.8%) were anti-HCV positive by a 1st-generation assay (ELISA, Ortho/Chiron) and confirmed positive in 35 (10.2%) with a 2nd-generation test (UBI, New York). Anti-HCV positivity was significantly associated with: duration of renal replacement therapy (P < 0.0001); quantity of blood transfused (P < 0.002); duration of hospital haemodialysis (P = 0.0001); duration with a functional renal transplant (P = 0.039); and aspartate aminotransferase (P < 0.0001). Logistic regression determined the following variables to be independent risk factors: duration of renal replacement therapy with a relative risk of 34.3 for 5-9 years and 87.4 when the duration was in excess of 10 years; renal transplant for less than 1 year (relative risk of 5.0); transfusion in excess of 50 units of blood (relative risk of 11.6). Clinical assessment of anti-HCV-positive patients revealed peripheral signs of chronic liver disease in 40%, hepatomegaly in 34%, and splenomegaly in 9%. This prevalence of hepatitis C infection is similar to other European and North American centres, but contrasts with low prevalence rates reported from dialysis populations in the UK. It adds further support for routine screening of blood and possibly organ donors and implementation of further infection control measures in dialysis centres.