This paper reviewed the clinical characteristics and treatment outcome of 484 lymphoma patients with known hepatitis B status. Comparisons were made between the hepatitis B surface antigen positive and negative patients. Also, the effect of treatment for lymphomas, including cytotoxic chemotherapy, in the hepatitis B antigen positive patients were analysed. The hepatitis B status was determined in 484 Chinese lymphoma patients at the time of initial diagnosis. Hepatic complications occurring during therapy for lymphomas were analysed. Although our lymphoma patients had a similar prevalence of hepatitis B markers of 42 per cent, they had a strikingly higher positive rate of 22 per cent for hepatitis B surface antigen and a relatively lower positive rate of 20 per cent for antibody, as compared to the respective figures of 9.5 per cent and 33 per cent in the control population. The hepatitis B surface antigen positive patients were younger than the negative patients but their treatment outcomes were similar despite the higher incidence of hepatic complications (21 per cent) in the hepatitis B surface antigen positive patients during therapy for lymphomas. None of the clinical parameters analysed appeared to be useful in predicting the development of these complications which included fatal liver failure (5.7 per cent), icteric hepatitis (5.7 per cent) and anicteric hepatitis (9.5 per cent). The high prevalence of hepatitis B surface antigen in our lymphoma patients may be related to the immunosuppressive effect of lymphomas. There is no definite evidence to suggest that hepatitis B infection has an aetiological or promoting role in the pathogenesis of lymphomas. Hepatitis B infection has contributed to the high incidence of hepatic complications during therapy for lymphomas and possible ways of prevention need to be investigated.