Tuberculosis and other mycobacterial diseases are considered to be one of the most important problems of contemporary health service. Since 1985 and particularly in the 1990s and at present the search for new structures of antimycobacterial agents have ranked amon~ the foremost areas of chemotherapeutic research. The present review paper is already the 17t communication in a group of review papers about the development of new antituberculotics, the sixth about the development in retem 15 years and the second communication devoted in this series to ortho-condensed heterocyclic compounds. The classification of ortho-condensed compounds is based on six-membered heterocyclic substructural fragments. The literature search is based on the journal Chemical Abstracts, Current Awareness in Biomedicine, part Mycobacteria, and original papers. Current Awareness in Biomedicine is, however, a very imperfect literature search source, recording only a fraction of communications.

        Key words: tuberculostatics - heterocycles - mycobacteria