Alpha-1 antitrypsin (1-AT) is a secretory glycoprotein mainly produced in the liver and monocytes. It is the most abundant serine protease inhibitor in human plasma. Proteolytic enzymes play a significant role in the expression of the malignant phenotype, including the loss of growth regulation, invasiveness and formation of metastases. Deficiency of 1-AT is an inherited disorder characterized by reduced serum level of 1-AT. Protease inhibitors Z (PiZ) and protease inhibitors S (PiS) are the most common deficient genotypes of 1-AT. The association of deficient 1-AT subtypes with several tumors such as primary liver carcinoma, lung cancer, bladder cancer and malignant hepatoma was reported. This study aimed to determine the incidence of 1-AT genotypes (PiZ and PiS) in breast cancer female patients. Blood samples were collected from 111 patients. DNA was isolated and the PCR technique was performed to amplify the regions contain the Z and S mutations in exon V and exon III, respectively. Genotyping of the Z and S alleles was performed by restriction fragment length polymorphism analysis using the Taq1 restriction enzyme. Our results demonstrated that 100% of the breast cancer patients were homozygous for the normal allele (PiMM) and no PiZ and PiS genotypes were found.