For the past several years the number of women suffering from chronic obstructive pulmonary disease (COPD) has been steadily increasing. This fact prompts the debate which factors, in addition to considerably increasing prevalence of cigarette smoking among young women, are responsible for these epidemiologic changes. Differences in the natural history and prognosis of COPD in females and males are presented in the paper, as well as the number of potential ethiopathogenetic and pathophysiologic factors influencing these variations. Among them, differences in the COPD risk factors spectrum in both genders and in airways anatomy are pointed out, and the mechanisms responsible for greater women's susceptibility to components of cigarette smoke, which reflect genetic (enzyme polymorphisms), epigenetic (diminished DNA methylation) and hormonal (estrogens) influences on xenobiotics metabolism. Further, sex-related differences regarding COPD phenotypes (chronic bronchitis vs. emphysema), immunological markers and clinical manifestation of disease are underlined in the paper. More frequent coexistence of anxiety and depression, COPD exacerbations and worse quality of life in women are also emphasized. Other differences, pointed out by authors include autoimmunological conception of pathogenesis of COPD (greater female susceptibility to produce autoantibodies), risk factors of disease exacerbation and, at last, response to certain forms of COPD treatment (nicotine replacement therapy, long-term oxygen therapy).