Breast cancer is initiated by exposure to endogenous and exogenous estrogens. A case-control (n= 250-500) study was undertaken to investigate the role of Single Nucleotide Polymorphisms (SNP's) in CYP17 (T34C), CYP19 (Trp39Arg) and FGFR2(C906T). Genotyping was done using the Taqman allelic discrimination assay for CYP17 (T34C) and FGFR2 (T906C) and PCR-CTPP for CYP19 (Trp39Arg). There was a significant protective association of the (TT/CC) genotype of the CYP17 gene against the risk of developing breast cancer (OR= 0.68, 95% CI: 0.49-0.96), which was more significant in postmenopausal women (OR= 0.56, 95% CI: 0.35-0.89) (p= 0.015). CYP19 (Trp39Arg) is a rare polymorphism and all the cases were homozygous for the wild type Trp allele (100%); this was also the case for 99.2% of the controls. We were unable to detect any variant form of the CYP19 gene in south Indian women. There was no significant association between the risk of breast cancer and FGFR2 (C906T). These results suggest that the CYP17 TT/CC genotype is associated with decreased risk for breast cancer, especially in post menopausal women.