Background : Functional Endoscopic Sinus Surgery (FESS) is a minimally invasive procedure for disease of Nose and Paranasal sinuses like chronic sinusits and polyps rhinosinusitis. Intraoperative bleeding causes poor visibility of surgical field is a major concern during FESS and this may results in many complication . Controlled hypotension is a technique where in arterial blood pressure is lowered in deliberate but controlled manner to minimize blood loss and enhance operative field visibility. Aim: To compare the hypotensive efficacies of intravenous Esmolol and intravenous Nitroglycerin in Functional Endoscopic Sinus Surgeries under general anaesthesia.In term of changes in heart rate ,systolic blood pressure, diastolic blood pressure ,mean arterial pressure, duration of surgery and operative field visibility assessment by surgeon by using Fromme scale. Methods: This study was conducted on total 60 patients, divided into two groups. Group Nitroglycerin (NTG) 30 patients , Group Esmolol (ESM) 30 patients.Patients between ASA grade I&II, age 18–60 years undergoing Functional Endoscopic Sinus Surgery under GA , Either injection Esmolol 100–300 mcg/kg/min and NTG groups 0.5 –10 mcg/kg/min through infusion pumps. All patient s were premedicated with Ondansetron (0.1mg/kg )IV,Midazolam(0.02mg/kg)IV,Glycopyrrolate(0.01mg/kg) and Fentanyl (2µg/kg) and then induced with Propofol 2mg/kg IV. Laryngoscopy and intubation was facilitated by Succinylcholine 2 mg/kg IV. Anaesthesia was maintained with Isoflurane vapour in balanced Nitrous oxide and Oxygen mixture and Vecuronium 1mg IV every 10–20 min for musle relaxation. Heart rate, Systolic Blood Pressure , Diastolic and Mean Arterial Blood pressure were assessed at 5min,10min,15min and so on upto 60 min. Result: Introperative Heart rate was less in Esmolol(ESM) as compared to Nitroglycerine(NTG) group. Both drugs produced desired hypotension but ideal operating conditions were achieved at a higher MAP of 80.74±2.6 mm Hg in ESM groups ,while same operating conditions, were achieved at lower MAP of 73.49±2.07 mm Hg in NTG group. Conclusion: Both drugs are safe and effective in providing optimal operating conditions but Esmolol is superior agent to NTG for controlled hypotension in FESS under general anaesthesia as it minimizes surgical blood loss, enhance operative visibility and reduces duration of surgery with minimal reduction in MAP . Absence of reflex tachycardia was added advantages of Esmolol over Nitroglycerin.