STUDY OBJECTIVE: The objective of the study was to compare intranasal fentanyl (INF) with intravenous morphine (IVM) for prehospital analgesia. METHODS: This was a randomized, controlled, open-label trial. Consecutive adult patients (n = 258) requiring analgesia (Verbal Rating Score [VRS] >2/10 noncardiac or >5/10 cardiac) were recruited. Patients received INF 180 mug +/- 2 doses of 60 mug at > or =5-minute intervals or IVM 2.5 to 5 mg +/- 2 doses of 2.5 to 5 mg at > or =5-minute intervals. The end point was the difference in baseline/destination VRS. RESULTS: Groups were equivalent (P = not significant) for baseline VRS [mean (SD): INF 8.3 (1.7), IVM 8.1 (1.6)] and minutes to destination [mean (SD): INF 27.2 (15.5), IVM 30.6 (19.1)]. Patients had a mean (95% confidence interval) VRS reduction as follows: INF 4.22 (3.74-4.71), IVM 3.57 (3.10-4.03); P = .08. Higher baseline VRS (P < .001), no methoxyflurane use (P < .01), and back pain (P = .02) predicted VRS reduction. Safety and acceptability were comparable. CONCLUSIONS: There was no significant difference in the effectiveness of INF and IVM for prehospital analgesia.