Introduction: Infertility is a disease. Estrogen is a hormone that plays an important role in the fertility. Estrogen receptor beta gene codes ESR2. expected that some genetic variations in estrogen receptor Infertility can be caused. The aim of the present study was to investigate the association between ESR-β gene polymorphism and infertility in Iranian women. Methods: In this study blood samples were collected from 50 infertile women and 80 healthy women and genomic DNA was extracted. PCR-RFLP method with RSa1 was used to identify in ESR-β gene. In addition, Allelic compounds and allele frequency in the population were determined, and the relationship between the polymorphisms and infertility in the population were examined using the chi-square test. Results: The results of this study indicated that there was no significant difference in the frequency of alleles A and G (P=0/5) between infertile and healthy women. Infertile patients with genotypes of AA and GG (P=0/8) did not show any significant association with infertility. However, the patients with AG genotype (P=0/001) demonstrated a strong association with the risk of infertility. Conclusion:Our findings indicated that ESR-β gene polymorphism are more likely realeted to women with AG genotype as well as with infertility.