BACKGROUND: The treatment for multi-drug resistant tuberculosis(MDRTB) is encountered to be important clinically, but there are still a few reports about it all over the world. So, we evaluated the outcomes of only chemotherapy for the pulmonary MDRTB retrosptctively. METHOD: We reviewed the clinical courses of 63 patients with pulmonary disease due to M.tuberculosis resistant to rifampin and isoniazid who were under follow-up between March 1996 and June 1996 after hospitalization at our hospital between January 1993 and January 1996. We performed cohort retrospective study for all these patient's records. Their regimens were selected individually and preferably included four medications that they had not been given previously and to which the strain was fully susceptible. RESULTS: The 63 patients(mean age, 43.2 years) had previously received a median 5.1drugs. Fifty two(82.5%) patients responded to chemotherapy(as indicated by negative sputum cultures for at least three consecutive months); eleven patients(17.5%) had no response, as shown by continually positive cultures. In a univariate analysis, an unfavorable response was significantly associated with greater number of resistant drugs before the current courses of therapy(relative risk 21.5; 95 percent confidence interval, 1.2-3.0; p<0.05). The mean period of follow-up was seventeen months. There was no relapse subsequently among the patients with responses. There was no death related to tuberculosis. CONCLUSION: In this report from National Masan Tuberculosis Hospital in Korea, multi-drug resistant pulmonary tuberculosis responded relatively well to carefully selected regimens.