Neurologic disease attributable to Parelaphostrongylus tenuis was diagnosed in five black-tailed deer (Odocoileus hemionus columbianus) relocated from Oregon to Tennessee. Mortality occurred in the pre-release enclosure and in the release area. Infection with P. tenuis was considered the cause of an unsuccessful stocking attempt. In addition, neurologic disease was produced by experimental infection of a black-tailed x white-tailed deer hybrid. Clinical and pathologic findings were described for black-tailed and hybrid deer, and epizootiologic aspects of P. tenuis infections were discussed.