Hepatocellular carcinoma (HCC) is one of the most common internal malignancies worldwide. Until recently, it has occurred relatively rarely in the West. Now, however, it appears to be rising in incidence in the United States and other developed western countries. The most frequent underlying factors causing HCC are chronic viral hepatitis and cirrhosis. Common clinical features include abdominal pain and worsening of hepatic synthetic function. More recently, however, patients with asymptomatic tumors are being diagnosed because of more frequent screening and improvements in imaging techniques. Early detection of HCC is a key factor in improving outcomes of therapies. There is growing evidence that HCC may be prevented with strategies aimed at preventing or treating viral hepatitis.