Background: Periodontitis is a risk factor for atherosclerosis and coronary heart disease (CHD). This research evaluated the relationship between periodontal conditions and postoperative outcome in patients undergoing coronary artery bypass grafting (CABG). Methods: 101 patients with CHD (age 69 years, 88.1 % males) and the necessity of a CABG surgery were included. Periodontal diagnosis was made according to the current classification of periodontal diseases (2018) and the guidelines of the “Centers for Disease Control and Prevention” (2007). Additionally, periodontal epithelial surface area (PESA) and periodontal inflamed surface area (PISA) were determined. Survival analyses were carried out after a one-year follow-up period with Kaplan-Meier survival plots and Logrank test. Hazard ratios (HRs) were determined using Cox regression. Results: 14 patients (13.9 %) suffered from a new cardiovascular event (11 x angina pectoris, 2 x cardiac decompensation, 1 x cardiac death). Patients with an event reported significantly more often tooth loss probably caused by periodontitis among 1st degree relatives, (HR = 2.2, 95 % CI 1.1-4.4, p = 0.006). No other periodontological parameter was significantly associated with the outcome. Internal risk factors were a history of peripheral arterial disease (HR = 3.7, 95 % CI 1.-11.4, p = 0.013), history of myocardial infarction (HR = 4.0, 95 % CI 1.4-11.5, p = 0.006) and borderline significant previous atrial fibrillation (HR = 2.9, 95 % CI 0.9-9.4, p = 0.056). Conclusion: Putative familial aggregation of periodontitis but not severity of the disease was associated with new adverse events after CABG surgery.