Background: Deficiency of alpha-1 antitrypsin (AAT1) is a rare disorder that represents a significant health threat and early diagnostic a priority issue. We investigate the usefulness of the serum protein electrophoresis (SPE) as an opportunistic screening tool for AAT1 deficiency. Methods: For 6 months, all SPE carried out for any reasons were evaluated in our center. In those with less than 3% of Alpha-1 globulins, AAT1 concentrations were studied. The SERPINA1 gene was subsequently sequenced in those subjects displaying concentrations below 100 mg/dL. Results: Out of the total, 14 patients (0.3%) were identified with low AAT1 concentrations, 11 of them agreeing to enter the study. Of those, mutations in the SERPINA1 gene were discovered in 10 subjects (91%). Heterozygous mutations were detected in 7 patients; 3 had the c.1096G>A mutation (p.Glu366Lys; Pi*Z), 2 the c.863A>T mutation (p.Glu288Val; Pi*S), one the c.221_223delTCT mutation (p.Phe76del; Pi*Malton) having the last one the c.1066G>A (p.Ala356Thr) mutation not previously described. Finally one patient had the c.863A>T mutation in homozygosis whereas two double heterozygous patients c.863A> T/ c.1096G>A were detected. Conclusions: an altered result in the concentration of AAT1 anticipates a mutation in the SERPINA1 gene in a manner close to 91%. The relationship between a decrease in the Alpha-1 globulin band of the SPE and an alteration in the AAT1 concentration is direct in basal states of health. The SPE is presented as a highly sensitive test for opportunistic screening of AAT1 deficiency.