An intradermal test for the diagnosis of BHV 1 (Intrakutantest Behringwerke AG) was applied to 53 nonvaccinated BHV 1-seronegative cattle aged 7 months to 8 years. Serologic blood testing performed subsequently using ELISA (Enzygnost-IBR/IPV, Behringwerke AG) and SNT revealed seroconversion in 24 of 45 animals without previous maternal antibodies. A second application of the intradermal test after these BHV 1-antibodies had declined, lead to a 'booster-effect' while a control group remained negative. Six of nine animals not affected by the first intradermal application of BHV 1-antigen, developed BHV 1-antibodies following the second intradermal test. Eight animals possessing maternal antibodies showed no serological response to the intradermal test at all. Present results strongly suggest an induction of humoral BHV 1-antibodies by the intradermal application of inactivated BHV 1. Consequently, the indirect control of BHV 1 infections, especially in cattle breeding farms, should be done exclusively by serological examination.