Two turkey adenoviruses were isolated from poults with respiratory disease, and their physicochemical properties were studied. The virus particles were unenveloped. contained DNA genome, replicated within the nuclei of infected cells, and were icosahedral in shape. Pathogenicity studies in poults indicated that North Carolina Kennedy isolant was a pathogen of relatively low virulence whereas the North Carolina Jackson isolant was nonpathogenic in commercial turkey poults.