Effects of estrogen on the cardiovascular system, mediated mainly by estrogen receptor type alpha (ER alpha), have been well-defined and specific polymorphisms in the ER alpha gene (ESR1) have been associated with several coronary heart diseases including coronary artery disease (CAD) in studies covering different populations. In the present study, we aimed to investigate whether there is an association between two of the known polymorphisms in the ESR1, named c. 454-397T >C and c.454-351A>G, and CAD in a Turkish population. One hundred sixty-eight patients with CAD and 99 patients without CAD were included in the study. The ESR1 c. 454-397T > C and c. 454-351A > G polymorphisms were studied by the conventional polymerase chain reaction-restriftion fragment length polymorphism (PCR-RFLP) method. While no association was found between the c. 454-351A > G polymorphism and CAD, the c. 454-397T >C genotype distributions were statistically significant independent of known risk factors between CAD-positive (CAD+) and CAD-negative (CAD-) groups (p = 0.001). TT genotype was more frequent in CAD- group than in CAD+ group, 22.2% and 4.8%, respectively. CC genotype was associated with increased risk of CAD (p = 0.001) compared to the TT genotype. When comparing the distribution of CC + TC genotypes to that of TT genotype in CAD+ and CAD- groups, the frequency of CC + TC genotypes showed a significant increase independent of known CAD risk factors in CAD+ subjects (p = 0.001). As a conclusion, a statistically significant relationship between the ESR1 c. 454-397T >C polymorphism and CAD were found independent of known CAD risk factors in a Turkish population.