Two case reports of deep hand infections with Mycobacterium avium-intracellulare are presented. Both occurred in elderly men. Aggressive surgical débridement combined with antitubercular chemotherapy resulted in an excellent outcome in both cases. Atypical mycobacterial infections should be considered in the differential diagnosis of any patient with prolonged and progressive tenosynovitis. A complete history, including temporally remote inoculation injuries or immunocompromised host status, should be elicited. Acid-fast staining and mycobacterial cultures, including reduced-temperature cultures, must be included in the diagnostic evaluation. Therapy should include immediate and aggressive surgical débridement, as well as appropriate chemotherapy.