Bovine viral diarrhea virus (BVDV) and Bovine alphaherpesvirus-1 (BoHV-1) have long been recognized as major causes of reproductive disease in beef and dairy cattle. Enhancing immunity through prebreeding vaccination and annual revaccination of the cowherd provide important contributions to limiting reproductive losses associated with these viral infections and are also important control procedures to limit transmission of these viruses among cattle populations. While providing efficacy, vaccination should also be safe. Safety concerns are often associated with the BoHV-1 fractions, while efficacy concerns are often associated with BVDV fractions of multivalent vaccines. Vaccination against BVDV and BoHV-1 effectively decrease risk of fetal infection, including abortions, birth of persistently infected BVDV carriers, and pregnancy loss. Safety concerns associated with viral vaccines, more specifically modified-live viral vaccines, should not overshadow the protective effects associated with sound vaccination principles and programs.