The treatment of mycobacterial infections has become an even more important and challenging problem because of the emergence of multidrug-resistant organisms and because of the immuno-deficiency sindrome (AIDS) pandemic, which has been associated with a market increase in tuberculosis and infections caused by the Mycobacterium avium complex. Because the microorganisms grow slowly and the diseases often are chronic, patient compliance, drug toxicity, and the development of microbial resistance present special therapeutic problems.