Objective: Breast cancer is most common cancer among women in the world and one third women affected by this cancer. It is associated with somatic and genetic alternation in tumor suppressor genes and oncogenes. P53 gene is a most important tumor suppressor gene. It plays an important role in genetic stability. G to C polymorphism at codon 72 of p53 gene, it associated with increasing of cancer, such as lung, nasopharyngeal, colorectal and breast cancers. Materials and Methods: In this case-control study was conducted among 126 patients with invasive and insitu, and 99 control individuals, using blood extraction, in East Azerbijan. P53 codon 72 genotypes were identified using PCR-SSCP. Then three genotypes was confirmed by direct DNA sequencing. Results: In the control group, the genotype distribution of p53 polymorphism, showed 30.3%, 50.5% and 19.2% for the Arg/Arg, Arg/Pro, Pro/Pro. Genotypes, respectively. In the cancer group, the distribution was 44.4, 34.9 and 20.6 for the Arg/Arg, Arg/Pro and Pro/Pro genotypes, respectively. Distribution differences in the p53 codon 72 polymorphism between the cases and controls were statistically significant (p<0.05). Conclusion: This study indicate that p53 codon polymorphism is a genetic predisposing factor for breast cancer in samples of East Azerbijan. However, further studies are needed to determine the role of p53 codon 72 polymorphism in breast cancer.