Totally 2630 culture positive pulmonary tuberculosis cases were admitted in our hospital during 17 years from 1976 to 1992. Clinical and bacteriology status of this cases were compered retrospectively between 3 groups; 1938 cases with initial treatment, 513 cases with retreatment excluding chronic tubercle bacilli excreters (CTBEs) and 179 chronic tubercle bacilli excreters. Mean age of the groups of CTBEs is 50.9 years. Sex ratio of it is 4.3:1. These figures are similar to those of the group of the cases with retreatment. Mean age of these groups is higher than 45 years in group of cases with initial treatment. Sex ratio in these group is higher than 3.1:1 in group of cases with initial treatment. Proportion of cases with complication of DM in group of CTBEs is 16.1%, statistically significantly higher than 10% in group of cases with initial treatment and 9% in group of cases with retreatment. Most CTBEs show resistant to both INH and RFP in drug susceptibility test if 0.1 gamma is adopted as clinical concentration of resistance to INH. 40% of CTBEs show susceptibility to SM and 35% of CTBEs show susceptibility to EB in the test. However in a large proportion of these cases with susceptibility result in each of these drugs, more than 34% in SM and more than 40% in EB, effect of the drugs was not observed clinically. Therefore previous treatment history as well as the result of drug susceptibility test should be considered in choice of anti-tuberculosis drug for treatment of CTBEs.