Blood samples collected from 120 wild swine (Sus scrofa) in thirteen Oklahoma (USA) counties during 1996 were tested for antibodies against six viral and two bacterial diseases. No antibodies to swine brucellosis, pseudorabies, transmissible gastroenteritis, and vesicular stomatitis were detected. Antibody titers to one or more leptospiral serovars were found in 44% of the samples, the two most frequent serovars being Leptospira interrogans serovars bratislava (29%) and pomona (27%). Antibody against porcine parvovirus and swine influenza virus was detected in 17% and 11% of the swine, respectively. Two samples (2%) were positive for antibody to the recently emerged porcine reproductive and respiratory syndrome virus.