OBJECTIVES: To assess the cost of managing COPD (health care payers perspective) in a real life setting in Belgium. METHODS: A multi-centre observational study with data-collection in a retrospective way (one-year) was performed. A total of 38GPs and 15pneumologists participated. Patients consulting the physicians in Q4 2004 - Q1 2005 were eligible. Individual data-collection sheets per patient, evaluating the yearly medical resource use, were completed by each investigator. Diagnostic methods, COPD severity, as well as smoking habits were evaluated. RESULTS: A total of 460 patients were evaluated. Mean age was 66 years, males represented 68.70%. 40.43% of patients were smokers (average n pack-years 36.69, StErr 1.54), 50.22% ex-smokers. COPD diagnosis was made in about half of the patients by both clinical evaluation and spirometry. A total of 13% of the patients had mild COPD, 47% moderate, 30% severe and 10% very severe COPD according to clinical evaluation or spirometry (GOLD-guidelines). A total of 73% of the patients experienced at least 1 exacerbation during the 1-year-study-period. Yearly number of exacerbations ranged between 0 and 12 (average n : 1.37, median : 1.00). In most cases (69.64%), no hospitalisation was needed. If hospitalized, average hospital stay per exacerbation was 13.30 days (StErr 1.03). Yearly COPD-maintenance-treatment cost ranged between 390€ (mild) to €1117 (very severe COPD). Maintenance-treatment included a wide range of medications. Management of COPD resulted in a total yearly cost of €1810 (StErr 139.55, range €537 (mild COPD) - €5888 (very severe COPD)), including maintenance-treatment (€670, StErr 26.67), hospitalisation (€1073, StErr 130.16) and treatment of exacerbations (€67, StErr 6.78).CONCLUSIONS: Management of COPD is costly, mainly due to the cost of hospitalisations. For very severe COPD patients, yearly management costs increase up to almost €6000.