This report describes a case of Mycobacterium tuberculosis infection in a green-winged macaw (Ara chloroptera), confirmed by microbiologic and pathologic diagnostics, and notes a possible human-avian transmission. Clinical signs included cutaneous swellings, profound leukocytosis, and signs of osteomyelitis in the long bones. Proliferation consisted of several nodules with small greenish-caseous foci in cross-section and revealed a severe granulomatous inflammation with intralesional acid-fast rods. Mycobacterium tuberculosis was isolated from subcutaneous nodules and biochemically confirmed. The disease in avian species is of zoonotic importance.