Chronic obstructive pulmonary disease (COPD) is a public health problem. Tobacco smoking is the major cause, but not the only one. Air pollution, exposure to chemical compounds, environmental smoke exposure, and environmental tobacco smoke are among other contributing causes; viral and bacterial infection are risk factors too. Gender and weight loss are associated to the severity of the disease. Co-morbidity is frequent. Objective: To characterize a population of COPD outpatients followed at a tertiary medical service. Methods: Questionnaires were applied to patients with COPD. The data included gender, age, weight, body mass index (BMI), oxygen delivery users, and FEV1, exposure to tobacco smoke, exposure to wood smoke, tuberculosis antecedent and co-morbid diseases. Results: Of the 70 patients enrolled in the study, 70% (49) were male with an average age of 64 ± 10 years, an average weight of 63 ± 16 kg and an average BMI of 22 ± 5 kg/m2. 45,7% were oxygen dependent and the FEV1 average was 35 ± 14%. Nine (12.8%) patients never smoked, while 78.8% had quit tobacco smoking, (38 ± 11 pack/years was the average). Nine (12.8%) smoked straw cigarettes. Eighteen (25.7%) had environmental exposure to wood smoke. Eleven (15.7%) patients had tuberculosis, 5.7% complained of asthma symptoms, 2.8% had bronchiectasis, 11.4% diabetes mellitus, 51.4% hypertension, and 20% Cor pulmonale. Conclusion: Other possible COPD etiologies must be investigated. Determinants for the pulmonary injury could be environmental smoke exposure associated to former infections. Men with low BMI are typically representative of this severe patient population. Hypertension and Cor Pulmonale are frequent co-morbidity factors.