Dendritic cells (DCs) are critical for both innate and adaptive immunity. Meanwhile, nitric oxide (NO) is a member of reactive nitrogen species (RNS) generally considered to play a key role in the bactericidal process in innate immunity against mycobacterium tuberculosis complex infection. The present study therefore investigated the mechanism of NO production in murine DCs induced by Mycobacterium bovis and its attenuated strain Bacillus Calmette-Gu eacute;rin (BCG) infection.