Background and Objectives: Preeclampsia is a challenging disease of human pregnancy that affects the mother and her foetus. It is a common obstetric syndrome of undefined aetiology affecting 7-10% of pregnant women. This study aimed to investigate the total antioxidant capacity (TAC), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, malondialdehyde levels, uric acid, vitamin C, and vitamin E levels in serum and saliva of preeclamptic and normotensive pregnant women with and without periodontitis. Methods: Sixty pregnant women, divided into four groups, preeclamptic women with and without periodontitis, and normotensive pregnant women with and without periodontitis, were recruited between 26 and 36 weeks of gestation from the Outpatient Department of Obstetrics and Gynaecology, KS Hedge Hospital, Mangalore. Pocket depth, clinical attachment loss, and gingival index were measured in all subjects. Saliva and serum levels of TAC, SOD, and GPx activities, malondialdehyde levels, vitamin C, vitamin E, uric acid were determined using spectrophotometer. Results: Comparison of sociodemographic variables among the study groups showed no significant differences. Salivary malondialdehyde levels were highest ( p = 0.025), levels of antioxidants vitamin C ( p = 0.027) and uric acid ( p = 0.013) being significantly lower in preeclamptic women with periodontitis. This group also had significantly lower serum levels of vitamin C ( p = 0.041) and SOD ( p = 0.004). Conclusions: The results of our study show that periodontal disease may be potential risk factor for severity, progression, and even initiation of preeclampsia because of reduced antioxidant capacity or increased oxidative stress. [ABSTRACT FROM AUTHOR]