Background: The CXC chemokine receptor 4 (CXCR4) and its ligand, stromal cell-derived factor-1 (SDF-Iα or CXC chemokine ligand 12) are involved in the trafficking of leukocytes into and out of extravascular tissues. The purpose of this study was to determine whether SDF-1α secreted by host cells plays a role in recruiting inflammatory cells into the periodontia during local inflammation. Methods: SDF-1α levels were determined by enzyme-linked immunosorbent assay in gingival crevicular fluid (GCF) of 24 individuals with periodontitis versus healthy individuals in tissue biopsies and in a preclinical rat model of Porphyromonas gingivalis lipopoly-saccharide-induced experimental bone loss. Neutrophil Chemotaxis assays were also used to evaluate whether SDF-1α plays a role in the recruitment of host cells at periodontal lesions. Results: Subjects with periodontal disease had higher levels of SDF-1α in their GCF compared to healthy subjects. Subjects with periodontal disease who underwent mechanical therapy demonstrated decreased levels of SDF-1α. Immunohistologic staining showed that SDF-1α and CXCR4 levels were elevated in samples obtained from periodontally compromised individuals. Similar results were observed in the rodent model. Neutrophil migration was enhanced in the presence of SDF-1α, mimicking immune cell migration in periodontal lesions. Conclusions: SDF-1α may be involved in the immune defense pathway activated during periodontal disease. Upon the development of diseased tissues, SDF-1α levels increase and may recruit host defensive cells into sites of inflammation. These studies suggest that SDF-1α may be a useful biomarker for the identification of periodontal disease progression.