Rheumatoid arthritis (RA), periodontal disease (PD), and coronary artery disease (CAD) are common chronic inflammatory diseases. RA is associated with accelerated vascular risk resulting in an increased prevalence of CAD with attendant early mortality and excess morbidity. RA and PD have a common pathobiology. Accordingly, the aim of this study was to evaluate the association between RA, PD, and CAD and the influence of systemic inflammatory factors. A total of 100 active RA patients of which 50 had established CAD and 50 had no CAD were assessed for PD. All subjects underwent a clinical, cardiac, dental, laboratory, and radiological evaluation. Blood samples were obtained, and the level of high sensitivity C-reactive protein (hs-CRP), total white blood counts (WBC), erythrocyte sedimentation rate (ESR), fibrinogen and tumor necrosis factor (TNF) alpha, total cholesterol (TC), and high density lipoprotein (HDL) were assayed. The findings of this study demonstrated an association between RA, PD, and CAD. The RA patients with CAD had significantly more PD than RA patients without CAD. The inflammatory markers, hsCRP, ESR, WBC, fibrinogen, and TNF-alpha, were raised in all patients but were significantly higher in RA patients with CAD who also had PD. HDL levels were lower in RA patients with CAD when compared to RA patients without CAD. Evidence from this study shows an association between RA, PD, CAD, and systemic levels of the inflammatory mediators. The implication is that inflammation may be the central link between the chronic inflammatory, autoimmune disorders, and atherosclerosis.