Background: The purpose of this study was to compare the availability of propofol and fentanyl (P + F) with diazepam and morphine (D + M) for intravenous conscious sedation during third molar surgery. Methods: Forty patients without systemic disease were operated under IV conscious sedation administered by either of the two techniques. Monitoring consisted of continuous observation of pulse rate, blood pressure, oxygen saturation, and the respiratory rate and were recorded every 15 minutes. Cooperation score was measured 5 and 15 minutes after induction of IV sedation. Following the operation, the surgeon and patients completed questionnaires including pain visual analog scale, amnesia, and side effects. Results: The P + F group was significantly more cooperative than the D + M group. The side effects of D + M group included pain on injection, nausea/vomiting and abdominal pain. The side effects of P + F group included talkativeness, nausea/vomiting, temporary apnea, pain on injection and vertigo. Conclusions: In this study, there were following benefits in the P + F group; more cooperative status and less pain perception. But respiratory depression developed in some patients.