A competitive enzyme-linked immunosorbent assay was developed and compared with the serum neutralisation test for bovine pestivirus using 508 cattle sera and serial serum samples from a goat hyperimmunised with five bovine pestivirus isolates. There was 96.7% agreement between the two tests. The relative sensitivity of the enzymelinked immunosorbent assay compared to the serum neutralisation test was 95.2% and the relative specificity was 99.4%. The titres of individual animals in the assay did not show a close correlation with serum neutralisation test titres. This may be because the antibodies measured in the two tests are directed against different viral proteins. The enzyme-linked immunosorbent assay has the advantage of being quicker and cheaper than the serum neutralisation test. The configuration used in the ELISA means sera from all species can be tested for pestivirus antibody using the same set of reagents.