Sera obtained from 66 free-ranging Florida black bears (Ursus americanus floridanus) from three geographic areas of Florida (USA) between November 1993 and August 1995 were tested for antibodies to 13 disease agents. Antibody prevalences were 3 positive of 37 tested (8%) Coxiella burnetii, 37 of 66 (56%) Toxoplasma gondii, 3 of 61 (5%) blue-tongue virus/epizootic hemorrhagic disease virus (BTV/EHDV), 4 of 66 (6%) canine adenovirus-type l, 5 of 66 (8%) canine distemper virus (CDV), 10 of 62 (16%) canine parvovirus (CPV), 7 of 66 (11%) eastern equine encephalitis virus, 4 of 66 (6%) western equine encephalitis virus, 2 of 66 (3%) Venezuelan equine encephalitis virus, and 11 of 66 (17%) St. Louis encephalitis virus. No samples had serologic evidence of exposure to. Brucella spp. (n = 37), Francisella tularensis (n = 40), or pseudorabies virus (n = 37). This is the first known published report of antibodies to B1V/EHDV, CDV, and CPV in black bears.