Potential risk factors for the development of primary hepatocellular carcinoma and the prevalence and role of infection with viral hepatitis B and hepatitis C were investigated in 54 adult patients of Bangladeshi origin (45 male, age range 20-75 years), comprising 46 patients resident in Bangladesh (Group 1) and 8 patients who had emigrated to the UK 10-20 years previously (Group 2). Of the 46 patients in Group 1 (37 male), 16 had hepatocellular carcinoma, 10 had uncomplicated cirrhosis, and 20 had a clinical history of chronic viral hepatitis of more than 6 months' duration. Total hepatitis B virus marker positivity was 82.6%, significantly higher than in Group 2 patients (P < 0.001). Thirty-six per cent were hepatitis B surface antigen positive, 66% were hepatitis Be antigen positive and 45.3% were positive for hepatitis C virus antibody. Taking only the 16 patients with hepatocellular carcinoma, hepatitis B surface antigen positivity was 38%, hepatitis Be antigen 66% and positivity to hepatitis C virus antibody was 56%. The 8 patients with hepatocellular carcinoma in Group 2 were all male and aged between 45 and 56 years. Of these, 3 (38%) cases were positive for hepatitis B surface antibody and none was positive for hepatitis B surface antigen or antibody to hepatitis C virus (3 cases tested). Presenting features of HCC in the two groups differed with a short clinical history of tender abdominal mass in Group 1 and a gradual onset of jaundice in Group 2 UK-resident Bangladeshi subjects.