Liver cancer is the second leading cause of global cancer mortality. The major risk factors for hepatocellular carcinoma (HCC) are being addressed with success by prevention efforts. Vaccination against hepatitis B virus has reduced incidence of HCC in Taiwan and is partly responsible for lower rates in China. New infections with hepatitis C virus are low in developed countries because of prevention of posttransfusion infections and reduced exposure to HCV by drug users. Aflatoxin exposure has been reduced by better grain storage and dietary changes. Obesity, metabolic syndrome, and diabetes are increasing in developed and developing countries and will lead to more cases of HCC.