Myeloperoxidase (MPO) is a lysosomal enzyme found in the azurophilic granules of polymorphonuclear leukocytes. It is involved in the defense against periodontal bacteria, and is also able to mediate inflammatory tissue destruction in aggressive and chronic periodontitis. The aim of this study was to explore the association between MPO-463G/A gene polymorphism and aggressive periodontitis (AgP) and chronic periodontitis (CP). The study included 147 subjects. Probing depth (PD), clinical attachment loss (CAL), plaque index (PI), and gingival index (GI) were recorded as the clinical parameters. Genomic DNA was obtained from the peripheral blood of 32 subjects with AgP, 25 with CP, and 90 reference controls. We genotyped the MPO-463G/A polymorphism using the PCR-RFLP method. All data were analyzed using SPSS version 13.0 for windows. There were no significant differences between the CP patients and controls regarding MPO-463A/G gene polymorphism either in terms of allele frequency or genotype frequency of MPO-463A/G. However, either in terms of allele frequency or genotype frequency of MPO-463A/G, there were significant differences between the AgP patients and the controls. In conclusion, our data suggest that MPO-463G/A may be associated with increased risk of aggressive periodontitis in Turkish patients.