Nalbuphine [Nubain] isanagonist/antagonistanalgesic. Unlike conventional narcotic analgesic, it has no appreciable increase in the risk of respiratory depression. The ceiling effect for respiratory depression by nalbuphine provides a unique safety factor among potent analgesics. Also, Nubain has low abuse potential and lower incidence of common side effects like nausea and vomiting. Nalbuphine in a dose of 0.15 mg kg was studied as a supplement analgesic drug with topical analgesia in 25 patients undergoing bronchoscopy. Their mean age is 41.8 years and mean body weight 51 kg. Satisfactory operating conditions were provided with good postoperative analgesia, no side effects like chest wall rigidity, dyspnea or nausea and vomiting were recorded. Patients were hemodynamically stable. Blood gas analysis showed no changes in the first five minutes after induction by nalbuphine during endoscopy mild pH, PaCo2 changes towards the acidic side which was found insignificant. The PaO2 showed little changes if air was used and gave higher results when oxygen is administered as a line of safety. This technique was found satisfactory especially for critically ill patients