Bovine Viral Diarrhea Virus (BVDV) is a major pathogen of cattle in most countries. The main reservoir of virus in herds are BVDV persistently infected animals, which arise as a result of infection of the bovine fetus early in gestation. The spread of virus to the unborn fetus may be prevented by Vaccination of the dam. We describe in this report the production and initial testing of an inactivated subunit vaccine against BVDV. The vaccine is based on production of antigen in primary bovine cell cultures, extraction of antigens from infected cells with detergent, chromatographic purification, concentration, and insertion of antigens into immune stimulating complexes (ISCOMs). Vaccines based on two different Danish strains of BVDV were injected into calves and the antisera produced were tested for neutralising activity against a panel of Danish BVDV strains. The two vaccines induced different neutralisation responses, which seem to partly complement each other. The implication of these observations for successful Vaccination against BVDV is discussed.