This is the first report of a disseminated mycobacteriosis caused by Mycobacterium kansasii in a reindeer (Rangifer tarandus). A two-year-old female reindeer with a history of lethargy and dyspnea was diagnosed with multiple pulmonary abscesses radiographically. At necropsy the animal had severe diffuse granulomatous pneumonia and pleuritis with severe multifocal granulomatous m yocarditis, lymphadenitis, nephritis, esophagitis, enteritis, and thyroiditis. Impression smears of necrotic debris from granulomas contained numerous acid-fast bacilli. M. kansasii was cultured from pulmonary, renal, hepatic, and lymph node sections. M. kansasii is a slow-growing photochromogenic non-tuberculous mycobacterial species that causes disease in severely immunocompromised individuals (3,4,9). Due to the popularity of reindeer as animals for exhibition in children's zoos, petting zoos, and holiday exhibitions, diagnosis of Mycobacterium kansasii in a reindeer is a significant public health concern.