This discussion begins with the anti-leprosy drugs included in the standard WHO-recommended MDT treatment of leprosy: dapsone, rifampin, and clofazimine. Next, a number of newer antimicrobial agents that possess various degrees of bactericidal activity against M. leprae, such as the fluoroquinolones, the macrolides, and the tetracyclines, are discussed. These drugs have been described as effective in experimental infections in mice and in human clinical trials. The modes of action for most of the effective classes of drugs against M. leprae occur at the level of nucleic acid and protein synthesis. However, for many anti-leprosy drugs, the actual mechanisms of action are not known but inferred from studies of M. tuberculosis.