Hepatocellular carcinoma (HCC) is the fifth most common neoplasm, the major cause of death in patients with liver cirrhosis, and the third most common cause of cancer-related death in the world. The geographic distribution of HCC varies significantly and 80% of cases occur in developing countries (Far East and South Asia) where the prevalence of viral hepatitis is higher. The treatment of HCC is difficult because most patients are diagnosed when the tumour is in an advanced stage and is not amenable to potential curative therapy, thus prevention is the key to reducing HCC and its related morbidity and mortality. HCC is unique among cancers, occurring mostly in patients with a known risk factor. Ninety percent of HCCs develop in the context of chronic liver diseases and mainly in patients with cirrhosis. Viral hepatitis is the most common cause of HCC worldwide, followed by alcoholic liver disease (ALD) and other causes such as non-alcoholic fatty liver disease (NAFLD), genetic haemocromatosis (GH) and primary biliary cirrhosis in an advanced stage (III-V). In certain areas of the People's Republic of China, exposure to aflatoxin and HBV infection are thought to be responsible for the extraordinary high risk of HCC. Substantial progresses in the prevention of virusl-related hepatitis (screening of blood units, use of disposable sanitary tools, HBV vaccination) have been achieved in developed countries, but in the same areas, alcohol- and dysmetabolism-related HCCs are emerging problems which require specific interventions in terms of public health measures. In developing countries, economic constraints limit the development of any program for the prevention of viral hepatitis transmission (including health education campaigns, healthcare politics, primary prevention and the improvement of hygienic and sanitary conditions). When viral liver disease is established, only a minority of patients are treated worldwide and benefit a possible preventive effect of medical treatment on HCC development. Thus the real contribution of medical treatment to HCC prevention in patients with chronic viral hepatitis is small. Great efforts are needed to identify more effective medical measures for primary and secondary prevention of HCC.