BACKGROUND: Induced hypotension reduces blood loss in the surgical field and provides better visibility. For induced hypotension, many methods have been used. Recently esmolol is favored in induced hypotension because of its short action and easy controlability, but thoracic epidural block is seldom used in induced hypotension. So we compared the effect of esmolol and thoracic epidural block in induced hypotension. METHOD: Patients scheduled for spinal posterior fusion under general anesthesia were randomly divided into two groups. In thoracic epidural group (Group I, 20 patients), 8~10 ml of 2% lidocaine was injected into the epidural catheter located in T6-7 interspace in a bolus. In esmolol group (Group II, 20 patients), 0.5 mg/kg of esmolol received as loading dose and 50~150 microgram/kg/min infused continuously. We measured mean arterial pressure, central venous pressure, heart rate, amounts of administrated fluids, urine output and VAS score. RESULT: There were no statistically significant differences between the two groups in amounts of bleeding, administered fluid, urine output. The elapsed time to reach the state of induced hypotension (MAP 55~65 mmHg) is 15.1 2.4 min after lidocaine injection in Group I and 6.1 2.7 min after esmolol injection in Group II (p<0.05). There were statistically significant differences between two groups in mean arterial pressure in 10 min after the injection (p<0.05). But there was apparent difference in VAS score in postoperative 1 hrs, 2 hrs and 6 hrs (p<0.05). CONCLUSION: Thoracic epidural block is another method for induced hypotension. And postoperative pain control can be easily achieved by injection through epidural catheter.