This paper reports the epidemiology of hospital-diagnosed acute viral hepatitis in U.S. Air Force personnel from 1980-89. First hospitalizations for viral hepatitis generally declined, ranging from 24.6 to 47.2 per 100,000 personnel. Hepatitis rates were higher among men, (RR = 1.3; 95% C.I., 1.1-1.5) and higher among blacks, compared to whites (RR = 1.4; 95% C.I., 1.3-1.6). Analysis of risk associated with various occupations demonstrated an increased risk of viral hepatitis for procedurally oriented medical personnel (physicians, clinical nurses, dentists) when compared to all other occupations (RR = 1.5; 95% C.I., 1.1-1.9). Pilots and navigators demonstrated a decreased risk of acute viral hepatitis. Members hospitalized for hepatitis B had a prior or concurrent diagnosis for sexually transmitted disease in 37% of cases; for drug abuse, 32% of cases. Serum samples from 332 individuals demonstrated that hepatitis A had the highest rate of agreement (84%) between serology and hospital discharge diagnosis. Only 3% of individuals with the diagnosis of NANB hepatitis were positive for hepatitis C.