This study was performed for the comparison of the therapeutic efficiency between 6-month (2HERZ/4HER) and 9-month (9HER) short-course chemotherapy under the programe conditions for pulmonary tuberculosis in terms of sputum AFB negative conversion rate, remedial interruption rate and cost effectiveness analysis. Two hundreds and ninty three patients treated with 9HER and 641 treated with 2HERZ/4HER had been discharged from 22 health centers in Seoul from May 1, 1993 to April 30, 1994. Seven hundreds and seventeen was subsequently analysed excluding 217 patients due to remedial interruption. The results : 1. Bacteriological negative conversion rate in 9HER regimen and 2HERZ/4HER regimen was 97.8% and 96.4% respectively(p>0.05). But the early treatment period, negative conversion rate in 2HERZ/4HER regimen was very higher than in 9HER regimen(p<0.01). 2. Remedial interruption rate for 9HER regimen and 2HERZ/4HER regimen was 34.1% and 13.6% respectively. The primary reason for the interruption was transfering to other clinics and this interruption was high within 3months. 3. Cost effectiveness for 2HERZ/4HER regimen was higher than 9HER regimen. The difference cost effectiveness ratio was 2.33 at the first sputum test and 1.69 at the last sputum test.