Patient records from the Guam Cancer Registry were compared with patients listed in a health department viral hepatitis case registry and the numbers of liver cancer and viral hepatitis cases were compared by ethnicity. Hepatitis C was the form of viral hepatitis most common among liver cancer cases on Guam (63.3% of viral hepatitis-associated liver cancer cases). Since viral hepatitis is an important cause of liver cancer, studies such as the present one may provide the information necessary to establish programs (screening of populations at risk and infant vaccination in the case of hepatitis B, for example) that may lessen the impact of liver cancer in the future.