Serum samples from 427 hunter-killed wild boar (Sus scrofa) from Slovenia were tested for antibodies to Aujeszky's disease virus (ADV). Samples were collected throughout Slovenia and corresponded to 6.2% of the total harvest. Antibodies against ADV were detected in 111 sera (26%) using a commercial enzyme-linked immunosorbent assay (ELISA). Antibody prevalence increased significantly with age. This report describes the first evidence of ADV infection in wild boar populations in Slovenia.