A disseminated infection caused by Mycobacterium avium subspecies avium (MAA) was diagnosed in a 57-yr-old male Asian elephant (Elephas maximus) housed at the Seoul Zoo, Gyeonggi, Republic of Korea. An apparent granulomatous inflammation with central caseous necrosis was evident in the lung sections. To confirm mycobacterial infection, polymerase chain reaction–restriction enzyme polymorphism analysis (PCR-RFLP) of the rpoB and hsp65 genes was performed from multiple organs and cultured bacteria. The PCR-RFLP revealed a M. avium subspecies. MAA was identified by multiplex PCR for detection of IS901 and IS1311. Thus, it is believed that MAA caused the disseminated infection in this case. Although the source of infection was not determined, the elephant may have become infected through contamination of soil and feed by free-living birds infected with MAA. This is the first reported case of disseminated infection due to MAA in a captive elephant in the Republic of Korea.