Abstract This study was performed in Korea to get serological information for bovine herpesvirus 1 (BoHV-1), most commonly found in cattle. Antibodies against BoHV-1 were examined by targeting infectious bo-vine rhinotracheitis (IBR) in unvaccinated and vaccinated cattle, using viral neutralization (VN) test. In 2013, among 261 sera collected from IBR-unvaccinated herds, 7 sera (2.7%) were found seropositive and their VN titers were ranging from 1:4 to 1:32. Among 315 sera collected from IBR-vaccinated herds in large capacity farms, 303 sera (96.2%) were found to be seropositive for BoHV-1 and their VN titers were in the range of 1:4 to 1:2048. It was found that the IBR-vaccinated herds had higher levels of VN titer than IBR-unvaccinated herds. The results indicated that it may be due to heavy vacci-nation in vaccinated herds and no or a little infection in unvaccinated herds. At the end of the study it was concluded that although the seropositivity in IBR-unvaccinated herds was low, the monitoring of IBR should be continuously practiced to control and prevent the disease because of exportation of living cattle causing its nationwide outbreaks.