Despite a reduction in newly acquired hepatitis B virus (HBV) infections since the mid-1980s, HBV remains an important cause of liver disease in the U.S. We report the prevalence of chronic HBV infection in a U.S. community and describe demographic and clinical characteristics. The Rochester Epidemiology Project records healthcare encounters of residents of Olmsted County, Minnesota. For all cases with a potential diagnosis of hepatitis B in this database, complete medical records were reviewed to identify subjects who met the inclusion criteria, i.e., a clinician diagnosis of chronic HBV infection and a laboratory record of positive hepatitis B surface antigen (HBsAg). There were 191 residents with chronic HBV infection in the community, consisting of 53% Asian, 29% African, 13% Caucasian, and 5% other or unknown race. The overall age-and sex-adjusted prevalence of HBV in this community was 0.15% in 2000. The race-specific prevalence was highest among Asians (2.1%), followed by African Americans (1.9%). The prevalence among Caucasians was 0.02%. Overall, 86% were born outside the U.S., 98% of whom were non-Caucasian. A total of 131 residents were tested for HBV replicative status, of whom 27% had viral replication. Of those tested for aminotransferases (n β«Ψβ¬ 184), 28% had an abnormal value at least once. In a multivariable regression analysis, replicative status was the most influential (odds ratio [OR] β«Ψβ¬ 5.98, P < .01) factor associated with abnormal aminotransferase values, followed by male gender (OR β«Ψβ¬ 3.69) and age greater than 40 years (OR β«Ψβ¬ 2.32 per decade). In conclusion, in this Midwestern community, chronic HBV infection was predominantly seen in immigrants from endemic parts of the world. (HEPATOLOGY 2004;39:811-816.) A ccording to the Centers for Disease Control and Prevention, the incidence of newly acquired hepatitis B virus (HBV) infection in the U.S. has declined steadily since the mid-1980s. [1][2][3] This trend has been attributed to a number of public health interven-tions such as screening of pregnant women and vaccination of infants and adolescents, as well as safe injection practices in general. 4 While reduction in the incidence of new infections is expected to reduce and eventually eliminate the pool of individuals for endogenous transmission, the prevalence of chronic hepatitis B has yet to show a decrease. Indeed, in a comparison of the second and third National Health and Nutrition Examination Surveys (NHANES), hepatitis B surface antigen (HBsAg) was found in 0.3% of the population from the former survey (NHANES II, 1976 -1980) and in 0.4% of the latter (NHANES III, 1988 -1994). 5 While these figures may not appear strikingly high, the prevalence of HBV infection (HBsAgΟ©) was approximately one-third of that of hepatitis C infections (HCV-RNAΟ©) in the NHANES-III sample (1.3%). In both NHANES samples, however, there was wide variability in the prevalence of HBV by race and ethnicity. For example, the prevalence of antibodies against HBV core antigen (anti-HBc) was lowest among non-Hispanic Whites (2.6%), followed by Mexican-Americans (4.4%), and non-Hispanic Blacks