An oral-oropharyngeal form of human anthrax is described in 24 individuals. The cases occurred as an epidemic in northern Thailand, concurrent with an epidemic of the common cutaneous form. This syndrome is a potentially fatal, febrile illness, characterized by a mucosal lesion in the oral cavity and/or oropharynx which can progress to pseudomembranous necrosis, and to cervical adenopathy and edema. Cattle and water buffaloes, recently arrived from Burma and eaten raw or undercooked, were the probable source of the infection. Determination of etiology was based on both microbiologic and epidemiologic evidence. The clinical syndrome and epidemiology are discussed.