Introduction: Periodontitis is a multifactorial and infective oral disease leading to the destruction of the periodontium. Detecting periodontal disease with biomarkers will help in the diagnosis and assessment of prognosis. Reactive oxygen species (ROS) are produced by polymorphonuclear neutrophils (PMNs), during phagocytosis and digestion of periodontal pathogens. The reactive nature of ROS leads to oxidative stress causing host tissue damage locally and systemically. 8-Hydroxy-2-deoxyguanosine (8-OHdG), an oxidative stress biomarker, is implicated in inflammatory disease pathogenesis. The present study evaluated the 8-OHdG concentrations in saliva and serum of healthy subjects and periodontitis patients.