The putative risk factors for hepatocellular carcinoma (HCC) are several, even in countries endemic for hepatitis B virus (HBV) infection. Cirrhosis characterizes more than 90% of HCC cases. The phases of inflammation, necrosis and regeneration, present for long periods in cirrhosis, might be most relevant in hepatocarcinogenesis. It is not clear what role is played by sex hormones while alcohol probably has a promoter role. Aflatoxins are known carcinogenins in the experimental animal: however it is difficult to evaluate the impact in human carcinogenesis due to the lack of reliable methods of measuring aflatoxin exposure in population studies. In conclusion, the aetiology of HCC is multifactorial and the main risk factor resides in the presence of underlying chronic liver disease