The influence of associated viral hepatitis status on 119 patients with primary hepatocellular carcinoma (HCC) undergoing hepatic resection was investigated. Operative morbidity and mortality were examined in three patient groups: 31 patients (group B) positive for hepatitis B surface antigen (HBsAg), 14 (group Be) positive for both HBsAg and hepatitis B e antigen, and 74 (group C) positive for hepatitis C virus antibody (HCVAb). Preoperative liver function in groups Be and C was similar and more impaired than that of patients in group B; combined active hepatitis was seen most frequently in group C (68 per cent). The tumour size in group B was significantly greater than that in groups Be and C. Postoperative complications occurred more frequently in group C (39 per cent) and early postoperative deaths, other than those from cancer, were seen in nine patients positive for HCVAb, of whom three developed postoperative liver failure. Patients with HCC and hepatitis B without seroconversion as well as hepatitis C frequently have active hepatitis, which may impair liver function and play an important role in operative morbidity and mortality.