Alpha 1-antitrypsin (AAT), the main protease inhibitor of human sera, was studied in a group of 88 children suffering from different pulmonary diseases, with the hope that some of the potential victims of chronic obstructive lung diseases can be identified in time. AAT genetic phenotypes were determined using acid agarose gel electrophoresis, followed by crossed antigen-antibody electrophoresis in agarose gel. Identification of the banding patterns revealed 10.2% of AAT variants. 4.54% of the patients were MZ, 3.40% were MS and 89.77% were MM. During this study, 1 FF and 1 MV subject were also found. All AAT variants were in the group of younger children, under 6 years of age.