Tuberculosis (TB) is caused by Mycobacterium tuberculosis (M.tb), resulting in significant increase in mortality rate worldwide. Immunity against M.tb consists of both innate and adaptive immunity, with emerging evidence of the role of the unconventional mucosal-associated invariant T (MAIT) cells. MAIT cells are MR1-restricted T cells that possess anti-bacterial activity, including activity in response to M.tb. To date, human studies regarding peripheral blood MAIT cell frequency and MAIT cell activity in TB patients are still controversial and most studies are cross-sectional.