Tumor growth and metastasis require the formation of new blood vessels, a process known as angiogenesis. One of the most important regulators employed in this process is the vascular endothelial growth factor (VEGF). The phenotypic effects of single nucleotide polymorphisms (SNPs) are based on direct genetic effects, gene-gene and gene-environment interactions. DNA sequence variations in VEGF gene might yield changes both in the production outcomes and in the activities of the gene. In this study, we aimed to determine how the changes in the YEGF -634G>C - a risk factor in the progress and metastasis of cancer - affect the gynecologic cancer patients in the Turkish population. A total of 100 gynecologic cancer patients (47 ovarian, 32 cervical and 21 endometrial) and 106 healthy controls were studied during the research. DNA extraction techniques were used to extract the genomic DNA from the whole blood. DNA analyses were carried out by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). There were no significant differences between any of the three types of gynecologic cancer patients and controls in terms of the distribution of VEGF -634 genotypes and alleles (p>0.05). Odds ratios (ORs) were calculated by logistic regression analysis in comparison with the most common homozygote genotype observed in studied population. Although, a statistically significant difference was found for genotypic frequencies of the -634G>C polymorphism between endometrial cancer patients with GC genotype and those with GG genotype (OR=027; 95% Confidence Interval (CI)=0.09-0.81; p=0.015), this result was not clinically significant due to its negligible OR. A multivariable logistic regression analysis performed on the covariates - family history concerning gynecologic and/or other cancer types, stages of tumor, smoking habits and existence of other diseases - did not change these results. This study is the first report demonstrating that the investigated YEGF -634 gene polymorphism is not associated with any of the three types of gynecologic cancer. © The Genetics Society of Korea.