This is a study of aetiological associations in patients with primary hepatocellular carcinoma (PHC). Thirty new patients with PHC were seen in a five-year period. The most common aetiological association was alcoholic cirrhosis. This was implicated in the development of PHC in 13 patients. However, since the introduction of radioimmunoassay for hepatitis B surface antigen (HBsAg) there have been six patients with HBsAg-associated PHC. Thus, for the first time, an association of hepatitis B virus with PHC is described in this country.