A review of pathological mechanisms that can explain the relationship between periodontitis and cardiovascular disease (CVD) is necessary to improve the management of both conditions. Metabolic syndrome is a combination of obesity, hypertension, impaired glucose tolerance or diabetes, hyperinsulinemia, and dyslipidemia. All these have been examined in recent years in terms of their relationship to periodontitis. Reviewed data indicate an association between some of them (body mass index, high-density lipoprotein-cholesterol [HDL-C], triglycerides, high blood pressure, among others) and periodontitis. Oxidative stress may act as a potential common link to explain relationships between each component of metabolic syndrome and periodontitis. Both conditions show increased serum levels of products derived from oxidative damage, with a pro-inflammatory state likely influencing each other bidirectionally. Adipocytokines might modulate the oxidant/anti-oxidant balance in this relationship.