Mycobacterium tuberculosis is the most important etiological agent producing pulmonary as well as extrapulmonary infection. During these last decades, the increase in the incidence of infection due to other mycobacteria species is evident. Lymphadenopathy is the most frequent extrapulmonary presentation form of Mycobacterium Genera infection among HIV positive patients either in developed or underdeveloped countries. The aim of this work is to analyze the results obtained during January 2007 - December 2009 in our laboratory Two hundred ten tissue samples were studied; 190 (90.4%) samples were lymph node biopsied tissues and 20 (9.5%) samples were obtained by fine needle aspiration; 17 were from HIV - patients (8.1%) and 193 from HIV + (91.9%). A total of 16 (7.6%) samples produced a positive culture for BAAR, 4 VIH- (25%) and 12 VIH+ (75%). Classification and identification for mycobacteria confirmed Mycobacterium tuberculosis in 13 of the cases (81.25%), and Mycobacterium avium-intracellulare in three patients (18.7%). The present study once again confirms that BAAR culture has more sensitivity and specificity than histopathologhic studies have. Lymphadenopathy in immunosuppressed patients should by studied for the presence of an BAAR coinfection where M. tuberculosis is still the agent most frequently found, nevertheless, other species of Mycobacteria may be causing infection and should be searched for. Our objective as National Reference Laboratory of Tuberculosis and Mycobacterial was to obtain the etiological characterization of Mycobacterium lymphadenopathy in clinically suspect patients.