OBJECTIVE: To determine the safety and effectiveness of fentanyl administration for prehospital pain management. METHODS: This was a retrospective chart review of patients transported by ambulance during 2002-2003 who were administered fentanyl citrate in an out-of-hospital setting. Pre- and post-pain-management data were abstracted, including vital signs, verbal numeric pain scale scores, medications administered, and recovery interventions. In addition, the emergency department (ED) charts of a subgroup of these patients were reviewed for similar data elements. RESULTS: Of 2,129 patients who received fentanyl for prehospital analgesia, only 12 (0.6%) had a vital sign abnormality that could have been caused by the administration of fentanyl. Only one (0.2%) of the 611 patients who had both field and ED charts reviewed had a vital sign abnormality that necessitated a recovery intervention. There were no admissions to the hospital, nor patient deaths, attributed to fentanyl use. There was a statistically significant improvement in subjective pain scale scores (8.4 to 3.7). Clinically, this correlates with improvement from severe to mild pain. CONCLUSION: This study showed that fentanyl was effective in decreasing pain scores without causing significant hypotension, respiratory depression, hypoxemia, or sedation. Thus, fentanyl citrate can be used safely and effectively for pain management in the out-of-hospital arena.