Mycobacterium marinum was isolated from lesions of two Bufonidae. Microscopic examination of tissues collected at necropsy of six Bufonidae revealed lesions containing acid-fast bacteria in the liver, lung, kidney, intestine and skin. Acid-fast bacteria occurred in alveoli and airways of lung and in lumen of intestine. Isolates obtained on mycobacteriologic examination were identified by tests for photochromogenicity, nitrate reduction and by seroagglutination tests.