Abstract : Electroconvulsive therapy (ECT) is one of the most effective treatments for many psychiatric disorders. Despite being a well-established as a safe method, ECT has many side effects such as cardiovascular complications. This condition may need special intervention or management during ECT, especially in patients with known cardiovascular disease. Esmolol and Labetalol are two beta blockers that could apply to keep patients off these complications. The present study aimed to compare the effect of prophylactic administration of Esmolol and Labetalol on heart rate (HR) and blood pressure (BP) in ECT. In this double-blind clinical trial study, 83 ECT candidate patients were divided into three groups randomly. Labetalol, Esmolol, and normal saline (as a placebo) were administered to groups first, second and third respectively. Collected data from HR and BP that had been recorded before, during, and after ECT were analyzed and interpreted. There were no significant different between three groups in mean of SBP, DBP and MBP. Mean of HR in Labetalol group and mean of SPO2 in Esmolol group were the lowest. Patients who were given normal saline had shorter recovery time with more tachycardia alternatively hypotension was observed in Labetalol and Esmolol groups further. Lower heart rate and diastolic blood pressure (DBP) in Esmolol and Labetalol groups respectively, suggested taking advantage of these medicines, especially in cardiovascular patients who are candidates for ECT.