Inherited alpha-1 antitrypsin deficiency (A1ATD) is listed among the three most common genetic disorders in Caucasians. It considerably increases the risk of progressive obstructive lung diseases, mostly chronic obstructive pulmonary disease. Data on the A1ATD prevalence in Poland are scarce, no studies with large enough groups representative for whole Polish population have been performed. Here, we present the preliminary data on the incidence of A1AT main deficiency alleles from the newborn screening in Mazovia (Central Poland) region. Real-time PCR genotyping and A1AT blood concentration measurement by nephelometry were performed from the dry blood spots (DBS) samples of 658 newborns. Deficiency alleles PI*Z i PI*S were present in 28 children, respectively in 2.8% and 1.5%. Their existence corresponded with significantly lower A1AT blood concentration. Estimated incidence of deficiency alleles was 13,7/1000 (95% CI 5.8-21.5) for PI∗Z and 7.6/1000 (95% CI 1.7- 13.5) for PI∗S. The calculated prevalence for the main deficiency genotype ZZ was 1/5345. The study is on-going.