The goal of this study is to compare the efficacy of morphine with that of nalbuphine on intraoperative bleeding in FESS operations. 68 patients, between 20 to 50 years old, were randomly 
grouped into two groups, 34 in each group. Group 1: received morphine 0.1 mg/ kg i.v 30 min before 
induction of anaethesia and group 2: received nalbuphine 0.1 mg/ kg i.v 30 min before induction. 
Both groups received nitroglycerin ( 0.5 – 10) mcg/kg/min at the start of procedure. Both drugs were 
successful to achieve a decrease in MABP with a significant statistical difference after 5, 15, 30, 45 
min, with no significant difference after 45,60,75, 90 and 105 min. There was no statistical significant 
difference between both drugs concerning the HR all over the procedure time. Morphine group 
needed lesser doses of nitroglycerine than nalbuphine group to achieve hypotensive anaesthesia with a 
statistical significant difference. No significant differences found between both groups concerning 
bleeding loss, post operative side effects (nausea, vomiting, shivering), surgeon satisfaction score, 
sedation score or recovery time.