A serosurvey was conducted during October and November 1989 to estimate the prevalence of selected arboviral, rickettsial, and Hantaan viral antibody among a sample of schoolchildren from 4 villages in the Bilbeis area of the Nile river delta, Egypt. Blood specimens were obtained from subjects aged 8 to 14 years. Enzyme immunoassay testing of the sera indicated that the prevalence of antibody was 9% (21/223) for Sicilian sandfly fever, 4% (8/223) for Rift Valley fever, 3% (15/437) for West Nile virus and 9% (28/315) for Hantaan (HTN) virus. Antibody was demonstrated among 22% (93/418) of the same study subjects against Coxiella burnetti, 53% (199/373) against Rickettsia typhi, and 37% (137/371) against R. conorii.