Aim To investigate the association of platelet endothelial cell adhesion molecule 1 gene polymorphisms with acute coronary syndrome.Methods We analyzed two single nucleotide polymorphisms of platelet endothelial cell adhesion molecule 1 gene Leu125Val and Ser563Asn in 117 angiographically documented patients with acute coronary syndrome and 117 age-and sex-matched controls in the Chinese population,using a polymerase chain reaction-restriction fragment length polymorphism strategy.Some samples were verified by direct sequencing.Results we found that two polymorphisms were in linkage disequilibrium with each other(D'=0.896)and that frequencies of 125Leu1 and 563Ser alleles were significantly increased in patients compared with controls(51.7% vs 39.7%,p<0.05;54.3% vs 42.3%,p<0.05,respectively).The frequencies of genotypes for 125Leu/Leu+ 125Leu/Val and 563Ser/Ser+ 563Ser/Asn were also significantly increased in the patients(p<0.05).In addition,there were no significant difference in patients among different vessel disease and between acute myocardial infarction and unstable angina.Conclusion platelet endothelial cell adhesion molecule 1 gene polymorphism may be a genetic risk factor for acute coronary syndrome.