P-selectin and P-selectin glycoprotein ligand-1 (PSGL-1) regulate the initial interactions between leukocytes, activated platelets and endothelial cells. Recently, a variable number of tandem repeats (VNTR) polymorphism in PSGL-1 gene affecting the length of the extracellular domain of PSGL-1 and the distance of the P-selectin binding site to the cell surface has been described. There are limited numbers of studies reporting PSGL-1 polymorphism might affect the inflammatory response and thrombosis. We explored the association between PSGL-1 VNTR polymorphisms (especially AB genotype that has the most deformed configuration of the binding site) and the development of coronary stent restenosis and stent thrombosis in patients with coronary artery disease (CAD). Eighty-seven patients with in-stent restenosis and 93 patients with patent coronary stents were included into the study. The distributions of age, gender, hypertension, diabetes, smoking, total cholesterol and triglyceride levels were similar between the groups. Genomic DNAs were obtained by standard methods from whole blood samples. Specific primers were used to amplify PSGL-1 gene by polymerase chain reaction (PCR). Three alleles and 5 different genotypes were detected. In the in-stent restenosis group; allele frequencies were 79.5% for A allele, 18.1% for B allele and 2.4% for C allele and in the patent stent group; allele frequencies were 79.3% for A allele, 20.1% for B allele and 0.6% for C allele. The allele frequencies were similar between the in-stent restenosis group and patent stent group (P = 0.97 for A allele, P = 0.73 for B allele and P = 0.19 for C allele). Genotype distributions were also similar between the groups. There were not any significant associations between PSGL-1 AB genotype and stent restenosis (31.3% vs. 27.2%, P = 0.54), repetitive stent restenosis (33.3% vs. 28.8%, P = 0.82) or in-stent thrombosis (44.4% vs. 28.2%, P = 0.37). In neither male patients nor female patients, there was any significant association between AB genotype and restenosis (32.2% vs. 24.3% P = 0.31 and 29.2% vs. 38.9% P = 0.51, respectively). However, among patients with a family history of early CAD, significantly higher percentage of AB genotype was found in those with stent restenosis (41.4% vs. 18.8%, P = 0.03). No significant association was found between PSGL-1 VNTR polymorphisms and in-stent restenosis. However, in patients with a family history of early CAD presence of PSGL-1 AB genotype might increase the risk of in-stent restenosis.