Hepatitis A is a self-limited, virally mediated infection of the liver. The usual mode of transmission is by the fecal-oral route. Employees of food-service establishments who are infected with the hepititus A virus can transmit the disease when handling food products. The Centers for Disease Control and Prevention recommends the use of the hepatitis A vaccine among dietary workers who may be at risk for contracting and spreading the disease. Because hepatitis A infection can often be a subclinical disease, the incidence of cases reported is not indicative of its true prevalence. The objective of this study was to document the seroprevalence of hepatitis A among hospital dietary workers. Dietary workers at a suburban hospital were interviewed to determine if they had been exposed to hepatitis A and if they had a history of hepatitis A infection. Serum was obtained from each subject and tested for the presence of hepatitis A antibodies. The Abbott HAVAB EIA kit was used for the detection of immunoglobulin G(IgG) and IgM hepatitis A antibodies. Of 119 subjects, 56 (47%) were women, and 63 (53%) were men; the subjects had a mean age of 42 years (range, 20-66). Fifty-one subjects (43%) were born in the United States, and 68 subjects (57%) were born outside of the United States. Of the 119 subjects, only 2 (2%) had a known history of hepatitis A infection, yet 67 (56%) had hepatitis A titers; 52 (44%) were susceptible to the disease. One subject had received the hepatitis A vaccine. Fifty-five of 68 foreign-born subjects (81%; 95% confidence interval, 71-91%) had hepatitis A antibodies versus 12 of 51 US-born subjects (24%; 95% confidence interval, 12-36%). The foreign-born subjects had a mean age of 28 years at the time of their arrival in the United States. In conclusion, a large number of foreign-born hospital dietary workers have hepatitis A antibodies without a history of disease. Immunization of this group of dietary workers may not have any beneficial effects, nor is it cost-effective.