Tuberculosis is one of the world's great public health crises. It is estimated by the World Health Organization that roughly one third of the world's populations, or some 2 billion people, are infected with Mycobacterium tuberculosis, the causative agent. More than 8 million people every year develop active tuberculosis disease, and 2 million die as a result. This article reviews tuberculosis and nontuberculous mycobacterial infections in older adults.