To characterize some epidemiologic characteristics of viral hepatitis among dentists, information was obtained with a mailed questionnaire from 434 dentists and 787 attorneys in Dade County, Florida. Dentists had a significantly higher incidence of hepatitis than did lawyers, 6.7% vs 2.4%, with the highest rate among oral surgeons (21%). The incidence of hepatitis B antigenemia among asymptomatic dentists was not significantly higher than that of volunteer blood donors. Twenty-two percent of dentists with hepatitis reported treating more than ten drug addicts per year, as compared with 10% of those dentists without hepatitis. No differences were noted between dentists with and without hepatitis in methods of sterilization, the wearing of gloves during procedures, or the use of disposable needles. The increased risk of hepatitis among dentists, however, may be related to the omission of adequate prophylactic measures, particularly when treating high-risk patients such as drug abusers. (JAMA 232:1228-1230, 1975)