OBJECTIVES: To describe the management of CB and COPD at stages 1 to 3 (SPLF classification, 1997) and to assess its cost in France. METHODS: In total, 409 CB and COPD patients were enrolled in the Broncheco cohort from November 2000 to October 2003 by 10 hospital chest physicians (HP), 50 private chest physicians (PP) and 63 general practitioners (GP). The cohort was followed for 1 year with data collection every 3 months: socio-demographic data, medical history and disease management (medication, oxygen, medical visits, medical procedures, hospitalisations and transportation). Inpatient costs were evaluated using the French Diagnosis-Related Groups and outpatient costs using the French nomenclature. Costs were expressed in 2003 Euro, according to the French societal perspective. Non-parametric statistical analysis was performed. RESULTS: In total, 316 patients were analysed (random drop-out was tested) with a mean age of 65 years, a history of the disease of 8 years, 75% were male and 37% were current smokers. The distribution in stages was: 21.5%, 42.1%, 22.8% and 13.6% respectively in stages 1, 2a, 2b, and 3. The annual cost (both medical and non-medical) was 794€, 1936€, 3938€ and 7706€ respectively for stages 1, 2a, 2b and 3 (p<0.001). The proportion of outpatient care in total cost decreased when stage of disease increased (94%, 70%, 63% and 62% respectively) while the proportion of inpatient care increased (6%, 30%, 37%, 38% respectively). For a same stage of disease, the costs were higher for HP, lower for PP and the lowest for the GP. High correlations between cost and age, length of disease and number of exacerbations were observed: 0.21, 0.23 and 0.49 respectively (p<0.001). CONCLUSIONS: These results showed that the cost of COPD was considerably greater in patient with advanced stage of disease. This would suggest the pertinence of early management of disease.