Objective. Our aim in this paper was to investigate the possible genetic association between three Ser563Asn, Leu125Val and Arg670Gly polymorphisms of the PECAM-1 gene and periodontitis. Methods. Genomic DNA was isolated fromwhole blood of 105 periodontal patient (52 with chronic periodontitis and 53 with aggressive periodontitis) and 101 healthy individuals. Samples were genotyped and analyzed for the three single-nucleotide polymorphisms (SNPs) of PECAM-1 using polymerase chain reaction with sequence-specific primers (PCR-SSPs). Results. A statistically significant difference was found between the genotypic distribution of the Ser563Asn polymorphism in patients with periodontitis compared to controls (P = 0.02). But there were no statistically significant difference between the allele frequencies in the different groups (P = 0.05). The other two polymorphisms did not show a statistically significant difference in their allele and genotype frequencies between the groups. There was no statistically significant difference found for any of the polymorphisms allele and genotype distribution in aggressive and chronic periodontitis either. Conclusions. No significant association was found between the polymorphism tested and the subgroups of periodontitis, further research is still necessary to determine whether this polymorphism can be used as a genetic marker of