Bovine tuberculosis is caused by Mycobacterium tuberculosis complex which infects a wide hosts range including humans and therefore it is considered as zoonosis. White-tailed deer (Odocoileus virginianus) is considered as reservoir of bovine tuberculosis, playing an important role on the disease epidemiology. The aim of this study was to determine the presence of M. tuberculosis complex in free-ranging White-Tailed Deer (WTD) in Tamaulipas, Mexico. During the 2009-2010 hunting season, 44 mandibular lymph nodes and tonsils from WTD were collected, processed by routine histopathology, Ziehl Neelsen staining, mycobacterial isolation and PCR. From those, 4.5% had gross changes. Histopathology revealed morphological changes suggestive to tuberculosis such as macrophage aggregation, necrosis, giant cells, mineralization and Bacilli Acid-Alcohol Resistant (BAAR). Abscedative type changes were also observed. The presence of M. tuberculosis complex by amplification of DNA from a tissue sample by PCR was confirmed. To the researchers knowledge this is the first mycobacterial report on WTD in Mexico.