The target animals and vaccination regimes for vaccines against the bovine rhinotracheitis (IBR) and the bovine viral diarrhoea virus (BVDV) are very similar. Therefore, we have compared different schedules for the combined use of a live IBR marker vaccine and an inactivated BVD vaccine. The neutralizing antibody response against BVDV did not reveal any differences between the group vaccinated only with the BVD vaccine and the groups that were vaccinated simultaneously (together in the same syringe) or concurrently (two separate injections) with the IBR marker vaccine at the first or second dose and the third dose of the BVD vaccine. Likewise, the bovine herpesvirus 1 (BHV-1) neutralizing antibody titres did not exhibit any negative effect by the simultaneous or concurrent use of the two products as compared to the single IBR marker vaccination. These results indicate that the two vaccines can be applied at the same day for the first or second dose of the BVD basic vaccination and then at the booster vaccinations (third dose onwards).