Based on the protease-antiprotease hypothesis in the pathogenesis of chronic lung diseases, we investigated the influence of Z and S mutations and TaqI-polymorphism of alpha1-antitrypsin gene (PI) and Ala - 15Thr polymorphism in signal peptide of alpha1-antichymotrypsin gene (AACT) in patients with COPD (n = 239), nonobstructive chronic bronchitis (n = 34), brochiectases (n = 33), chronic infant lung disease (n = 151) and cystic fibrosis (n = 57). The allele and genotype frequency of any genetic polymorphism was not statistically different between the groups and control subjects (n = 225). Furthermore, promoter polymorphism G - 1607GG in interstitial collagenase gene (MMP1) was determined in patients with COPD, chronic nonobstructive bronchitis and bronchiectases. In patients with COPD it was marked prevalence of mutant homozygous genotype GG/GG compared to controls (30.6 % and 18.0%, respectively, OR = 1.99; 95% CI 1.11-3.59). These findings suggest that genetic polymorphism in the promoter of MMPI gene may be associated with individual susceptibility to the development of COPD.