Introduction: The problem of chronic obstructive pulmonary disease (COPD) is important in the most of countries, despite of numerous anti-smoking campaigns. If in previous decades, morbidity and mortality from COPD among men was significantly higher comparing to women, in recent years these indicators became practically equal in patients of both sexes, moreover, in some countries they dominate in women. According to the worldwide statistics, nowadays COPD kills more women than breast and lung cancers that do together. Therefore, there is a need to research the gender peculiarities of clinical course of COPD. Materials and methods: The study was conducted on 42 men and women who are smokers and have COPD of the third stage. Age, number of pack-years of smoking, presence of comorbidities and number of exacerbations of COPD during the previous year were considered. Forced expiratory volume in first second (FEV1), the distance in meters, that the patient may walk for 6 minutes, severity of dyspnea by MMRC scale, body mass index (BMI) were assessed in all patients. Results: Among the patients with COPD the women were younger than men (respectively, 56 and 67 years, p <0.05), they smoked less (respectively, 37 and 58 pack-years, p <0.05), had lower BMI (respectively, 25 and 28, p <0.05), more exacerbations during the previous year (respectively, 1 and 0, p <0.05) and fewer comorbidities. Gender differences in FEV1 were not found. At the same time women with COPD were less tolerant to physical exertion (they could walk for 6 min 94% of the necessary distance, while the males – 102%, p = 0.05) and developed more significant dyspnea by MMRC scale (respectively, 3.5 and 2.2, p <0.05). Conclusions: There are some sex differences in the development and clinical course of COPD, which are caused, apparently, by specific neurohumoral regulation of bronchopulmonary system functions, hormonal influence on the metabolism of tobacco smoke and by different severity of oxidative stress that damages the bronchopulmonary tissue. Further study of sexual peculiarities of COPD may improve the effectiveness of treatment of this widespread disease.