Tissues and serum from white-tailed deer (Odocoileus virginianus) in the southeastern United States were taken during an outbreak of hemorrhagic disease. These were subjected to virus isolation attempts in tissue culture and several serological tests (plaque neutralization, complement fixation, agar gel precipitation). Both epizootic hemorrhagic disease of deer virus (EHDV) and bluetongue virus (BTV) were isolated and evidence of their presence demonstrated serologically. All of the evidence supported previous suggestions that these two agents are antigenically distinguishable.