OBJECTIVES: Assessment of direct and indirect costs of COPD exacerbations under usual clinical practice in primary and secondary care from societal perspective in Poland METHODS: An observational, prospective study was conducted among patients with exacerbation of moderate or severe COPD. All patients (n=197) were divided into two groups depending on place of care. The group treated in hospital care  (HC) and in ambulatory care (AC) adequatly oconsisted of 89 and 108 patients. The direct costs included cost of drugs, diagnostic tests, inhospital and outpatient care. We singled out one-day medical treatment facility costs for inpatients. The indirect costs included costs of work days lost. RESULTS: The mean duration of COPD exacerbation did not differ significantly between the groups (p>0.5, adaquately 9.5 and 8.8 days for HC and AC group). The total health care cost per exacerbation was €1410,0 (5078.50 PLN) in secondary care (the HC group) and it was 10.5 times higher than the total cost of exacerbation in primary care (the AC group) €134,3 (483.80 PLN) (according to course of currencies on 15 December 2007). The costs of drugs and diagnostic tests were significantly higher in the HC group than in the AC group, however it were facility costs of inhospital stay and medical visits in the HC group that influenced expenditures related to COPD exacerbations most tremendously, as they were 27 times higher than in the AC group. CONCLUSIONS: In Poland the costs of COPD exacerbation managed in secondary care are 10.5-fold higher than in primary care. Therefore, the decisions about admission of patients with COPD exacerbation to hospital should be made carefully.