Association between periodontal and cardiovascular diseases has been intensively investigated in recent years. The aim of this research was to determine the prevalence of aggressive and chronic periodontitis in patients who had angiographically verified coronary heart disease and also to compare the changes in patients with normal coronary angiographic findings. SYNTAX Score (Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) was calculated for every patient and compared with the periodontal status. Subjects were selected among the hospitalized patients at the University Hospital Centre Zagreb who had coronary angiography done because of the chest pain. Thorough clinical examination included periodontal indices and clinical and socio-demographic characteristics of participants. Subjects were divided in two test groups, acute coronary syndrome (ACS) and stable coronary artery disease (CAD), and the control group with no significant CAD. The research is based on the assumption that chronic infection may be a predisposing factor for the development of atherosclerotic cardiovascular disease, and therefore coronary heart disease and complications of coronary artery disease. In patients' peripheral blood sample a biochemical analysis was performed to determine hs-CRP, glucose, lipid levels, and presence of specific antibodies for Cytomegalovirus (CMV) and Epstein–Barr virus (EBV). Data were analyzed using Kruskal-Wallis and Pearson’s Chi-Square test. The association of aggressive and chronic periodontitis with the severity of coronary heart disease presented by SYNTAX Score was significant, P=0.003. We found a significant increase of physical quality of life in periodontally healthy patients (P=0.008), while the mental component was significantly more prevalent in patients with acute coronary syndrome. Biochemical analysis of peripheral blood showed no significant difference in hs-CRP. When compared to periodontal disease there was significant difference in the level of triglycerides (P=0.020) and HDL-cholesterol (P=0.008), while when compared to the severity of coronary heart disease presented by SYNTAX Score there was significant difference in levels of leukocytes (P=0.012), neutrophils (P=0,004) and triglycerides (P=0.019). All of our participants have had previous infection with EBV and most of our participants have had previous infection with CMV. This study showed that periodontitis is associated with angiographically verified coronary artery disease. Physical inactivity, poor oral hygiene and periodontal inflammation were observed in patients with ACS and stable CAD.