The reemergence of tuberculosis in the industrialized countries has hastened the development of new laboratory techniques. Hence, well-known shortcomings of traditional techniques such as the lack of a rapid and specific detection system, the delayed availability of species identification and drug susceptibility results, and the lack of a reliable method for determining strain identity for epidemiological purposes, have become immediate targets for implementing molecular biology techniques. In particular, nucleic acid amplification techniques, restriction fragment-length polymorphism and single-strand conformation polymorphism analyses have dramatically improved diagnostic timeliness and accuracy of mycobacteriology laboratory results. Our paper reviews recent developments and comments on the diagnostic applications of the new tools as compared to traditional techniques.