Most studies have evaluated serum C-reactive protein (CRP) levels in chronic periodontitis (CP) patients, and a few investigations have examined gingival crevicular fluid (GCF) CRP levels. The aims of this study were to determine GCF and serum levels of high-sensitivity CRP (HsCRP) in CP patients with or without coronary artery disease (CAD) and to investigate the relationship between the GCF and serum HsCRP levels in CP patients with and without CAD.