Results of an automated information system on bacillary tuberculosis and mycobacterioses (ISBT) operating in the Czech Republic since 1981 nation-wide have been employed in this study. This system collects and processes data reported by all mycobacteriology laboratories in the country (34 in 1993) on each person disseminating pathogenic and/or opportunistic mycobacteria, on pathological materials examined in these patients and on methods applied for detection and identification of isolated mycobacteria Results of the 1981-1993 period were analyzed in this study. The annual incidence of bacillary tuberculosis cases identified by culture fell down from 2655 (25.8 per 100,000 popul.) in 1981 to 1139 (11.0 per 100,000 popul.) in 1993, i.e. by 57.4% in total, and by 4.8% in average annually. The decrease of annual mean values differed between two periods, from 1981 to 1985 and from 1986 to 1993, being 8.7% in the first and 3.7% in the successive period. The incidence of cases detected by direct microscopy of sputum showed a decline from 615 to 410 cases (5.97 to 3.97 per 100,000 popul.) in the 1981 to 1993 period, i.e. 2.8% annually. The analysis of the development and of the present state of the bacillary tuberculosis is instrumental in estimating the today's burden of the tuberculosis problem in the Czech Republic. Although distinct sings of worsened epidemiological parameters were not shown in this study, some disturbing findings can be considered as alerting: (a) a slowdown of the declining trend of bacillary tuberculosis cases detected by culture techniques seen in a few recent years, and (b) conserving potential tuberculosis pools in patients suffering from serious forms of the disease detectable by direct microscopy.