Viruses were recovered from nasal exudates of two of nine calves with acute respiratory disease. The strains, designated VC484 and VC488, were neutralized markedly by guinea pig antiserum against the Long strain of respiratory syncytial (RS) virus. Physical and chemical properties of the isolates were characteristic of RS viruses. Cultures of infected primary bovine embryonic kidney cells developed numerous syncytial cells. Intracytoplasmic eosinophilic inclusions were present in syncytial and single cells. Infected cell cultures did not adsorb guinea pig erythrocytes, nor did infective culture fluids agglutinate guinea pig, rat, mouse, rabbit, calf, or horse erythrocytes. One of the two calves developed a significant increase in titer of antibody; the other calf had preexisting neutralizing antibody against both isolates. No other viruses were recovered. It is concluded that these calves were infected with bovine strains of RS virus, reported now in the United States.