Objective: To determine the incidence, short term survival and safety of delayed sternal closure following open-heart operation due to myocardial edema, non-surgical bleeding and malignant arrhythmia. Methods: We retrospectively reviewed our medical records to identify the patients who underwent delayed sternal closure following open-heart operation and recorded morbidity, mortality postoperative complications of these patients. Among 2698 patients who underwent on- pump cardiac surgery, the sternum was left open in 46 (1.7%) patients, 31 men and 15 women, ranging in age from 2 to 73 years (mean 57.0±7.6 years). In 39 patients sternum was left opened following the initial operation and in 7 patients sternum was re-opened due to bleeding or hemodynamic instability after initial surgery. Statistical analysis was accomplished using Chi-square test, Mann Whitney U test and analysis of variances for repeated measurements. Results: The operative procedures were classified as elective in 24 (52.8%), emergency in 10 (22%), urgent in 7 (15.4%), and redo cardiac operations in 5 patients (11%). Bleeding (n=21), hemodynamic instability (n=16), arrest (n=5), and arrhythmia (n=4) were the reasons of delayed sternal closure. The patients had an open sternum for 3.48±0.35 days. Time to discharge was 21.5±1.6 days after operation and 17.6±1.6 days after sternal closure. Mortality within 30 days was 23.9% (7 patients died before closure and the remaining 4 after closure). Complications were mediastinitis (n=2), minor wound infection (n=3) and renal failure (n=5). Conclusion: Delayed sternal closure is a safe and simple method for treating bleeding, arrhythmia and myocardial edema following on pump cardiac surgery. It is anticipated that as cardiac surgeons become more familiar with the technique of delayed sternal closure, the frequency of its use following on pump cardiac surgery may increase.