Twenty-three sera from a moose (Alces alces) population in southeastern Alberta were serologically tested for virus activity. No reactors were detected in a metabolic inhibition test in tissue culture to eastern encephalitis, vesicular stomatitis or encephalomyocarditis; there was one reactor to St. Louis encephalitis, two reactors to western encephalitis, and 16 reactors to California encephalitis. No positive reactors were obtained against bluetongue or epizootic hemorrhagic disease in plaque-reduction neutralization tests. This is the first report of serologic reactors to these diseases in moose and the epizootiological significance of these findings is discussed.