Chronic hepatitis B (CHB) infection is a major cause of human mortality worldwide. The majority of people with CHB are infected early in life, and 20-40% of men and 15% of women with chronic infection will develop hepatocellular carcinoma (HCC). Antiviral therapy is recommended for patients with CHB who have cirrhosis or active disease with the aims of reducing disease progression to cirrhosis, liver failure and liver cancer, thereby preventing death. Evidence that treatment with interferon or with early nucleos(t)ide analogue therapy reduces HCC has been somewhat conflicting, however evidence is emerging to support a significant role in HCC prevention of the more effective antivirals, entecavir and tenofovir. Older patients, those with cirrhosis, and those undergoing curative treatments for HCC derive the greatest medium-term benefit in terms of HCC reduction, but HCC can still occur and long-term surveillance is recommended.