BACKGROUND: An association between diabetes and tuberculosis has long ken implied. The severity of diabetes appears to correlate with the degree of tuberculous activity. METHODS: A retrospective chart review of 82 patients with active pulmonary tuberculosis in diabetics(DMTB) and 83 patients with active pulmonary tuberculosis in nondiabetios (Non-DMTB) admitted to the Kyung Hee Medical Center between January 1995 and December 1996 was undertaken. RESULTS: The sex ratio of DMTB was 58 : 24, and that of Non-DMTB was 62 : 21. Male patients predominated in both groups. The highest incidence of DMIB was 6th and 7th decades and that of Non-DMTB was 3rd and 4th decades. In case which the tuberculosis developed after diagnosis of diabetes, the prevalence of pulmonary tuberculosis was the highest in diabetes for 5 -10 years. On chest X-ray findings, the moderate advanced tuberculosis cases were the most common (60.9% in DMTB and 50.6% in Non-DMTB). There was no relation between the degree of tuberculosis activity on chest x-ray(minimal, moderata awl far advanced tuberculosis) and presence of diabetes. The incidence of lower lung field tuberculosis in DMTB was significantly higher than Non-DMTB(p<0.05). The multiple lobe involvement was the predominant chest roentgenograpflc finding in both groups. There was no significant difference of treatment response between DMTB and Non-DMTB. There was no relationship between initial HbA1c and the stverity of pulmonary tuberculosis on chest X-ray. During treatmenu of pulmonary tuberculosis in excellently and well controlled diabetes, the cure rate of pulmonary tuberculosis was sigrificantly higher than the pcorly controlled diabetes and the rate of treatment failure was significantly lower than poorly controlled diabetes. (p<0.05). CONCLUISON: Poor control of blood glucose is related with increased rate of treatment failure in pulmonary tuberculosis with diabetes mellitus. Further investigation will be needed to study the mechanisms of treatment failure in poorly controlled diabetics with pulmonaiy tuberculosis.