Diagnostic findings were reviewed on 157 sick or dead gray foxes (Urocyon cinereoar-genteus) from the southeastern United States examined during the period 1972 through 1989. Most foxes (n = 118) originated from Georgia; fewer animals were from Florida, Kentucky, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia and West Virginia. Etiologic diagnoses included canine distemper (n = 125), congenital absence of guard hairs (n = 7), traumatic injuries (n = 7), rabies (n = 3), suspected toxicoses (n = 3), verminous pneumonia due to Paragonimus kellicotti (n = 1), bacterial septicemia secondary to Dracunculus insignis (n = 1), and tick paralysis (n = 1). Concurrent toxoplasmosis or cryptosporidiosis was noted in six and three foxes with canine distemper, respectively. Only lesion diagnoses were attainable for three foxes, and six cases were classified as undetermined. Canine distemper was diagnosed in 78% of the foxes, was geographically widespread, was detected in 16 of 18 yr, and exhibited a seasonal pattern of occurrence. These facts indicate that canine distemper is more significant as a mortality factor for gray foxes than all other infectious and noninfectious diseases combined.