Abstract Background Beta-adrenergic receptor blockers have been studied for minimizing the effects of catecholamines by blocking their activation of beta receptors. They are used to prevent or treat hypertensive crises, tachycardia, ischemic cardiomyopathy, and arrhythmias. Several studies have shown the efficacy of such drugs in decreasing postoperative morbidity and mortality. Aim of the study This study aimed to evaluate the benefit of perioperative beta-blocker therapy in improving the outcome of CABG surgery regarding intra- and postoperative arrhythmias and ventricular function. Method It was a prospective controlled nonrandomized study conducted on 50 patients undergoing elective CABG in Ain Shams University hospitals, in which the study group, who were the patients who were compliant on beta-blocker therapy, received 1 mg of propranolol before removal of aortic cross clamp and continued on beta-blocker therapy in the postoperative period, while the control group who were not on beta-blocker therapy received an equivalent volume of normal saline before removal of aortic cross clamp and received beta-blocker therapy in the postoperative period. Both groups were assessed regarding the heart rate, ventricular systolic function by transesophageal echo intraoperatively and transthoracic echo postoperatively, duration of ICU and hospital stay, and incidence of intra- and postoperative arrhythmias. Results Perioperative beta-blockers decreased the incidence of intra- and postoperative arrhythmias. Conclusion In the absence of contraindications, CABG patients should receive perioperative beta-blockers as they improve the systolic ventricular function, decrease the incidence of intra- and postoperative arrhythmias, and shorten the duration of hospital and ICU stay.