There are many risk factors for coronary artery disease (CAD) and periodontal disease (PDD) is a controversial risk factor. The aim of this study was to show the association between CAD and PDD. A case-control study was designed. Sixty one patients that CAD was confirm in them by coronary angiography compared with sixty one patients with normal angiography. PDD was evaluated by two indices, gingival index and periodontal disease index. Odds ratio was calculated for the risk of PDD for CAD. The results were shown no differences between groups about sex, age, educational level and occupation. The odds ratio of periodontal disease for CAD was 58 with CI95% (51-65). The relationship between tooth frequency and CAD was not statistically significant. Finding of the current study suggested that periodontal disease is the risk factor for CAD. However more clinical studies especially prospective longitudinal studies were recommended.