Viral hepatitis is a complex of infections rapidly becoming better understood with the discovery of new viruses, the availability of various vaccines, and changes in dosage recommendations. Hepatitis B is reviewed as an infectious disease with serious implications for dentistry while discussing modes of transmission, frequency of infection, recent changes in hepatitis B vaccine dosage recommendations, a newly licensed recombinant vaccine and the current policies on pretesting, posttesting, booster doses, and vaccination of pregnant women. Current information is provided on recent outbreaks of both non-A non-B and delta hepatitis in the United States.