OBJECTIVES: The study evaluated the influence of tobacco smoking on direct costs of treatment of chronic obstructive pulmonary disease (COPD) exacerbations. METHODS: A total of 112 men who underwent treatment of COPD exacerbation in the Military Institute of Health Service from November 2001 to October 2002 were included in the study. The patients were qualified into one of three groups: I – never-smoking patients (n=40), II – former smokers (n=42); III - active smokers (n=30). RESULTS: The mean direct cost of exacerbation treatment was USD 686.2 (SD 292.3) [group I – 642.9 (SD 216.2); group II – USD 595.4 (SD 193.2); group III – USD 871.1 (SD 401.9)]. No significant differences in treatment costs were found between the group I and group II. The costs of inhospital treatment of COPD were significantly higher in the group III than in the groups I and II. A linear correlation was found between each consecutive pack year of addiction and the costs of exacerbation treatment in the group III (R=0.39, R2=0.13; p<0.03). No similar relationship was found in the former smokers' group. CONCLUSION: Active tobacco smoking by COPD patients is related to significantly higher direct costs of hospitalization due to COPD exacerbations.