Background & Aim: Pain management is a crucial aspect of care for trauma patients, as it significantly impacts both the patient and the treatment staff. Opioids are commonly used as analgesics for multiple trauma patients in the emergency department. However, due to their side effects, there is a need to explore alternative analgesic drugs that are safer yet equally effective. Therefore, this study aimed to compare the analgesic effects of ketamine nebulizer and intravenous morphine in trauma patients. Materials and Methods: In this double-blind randomized controlled clinical trial, we divided multiple trauma patients referred to the emergency departments of Shahid Sadougi and Rahnamon Hospitals in Yazd province during 2020-2021 into two groups: nebulized ketamine and intravenous morphine. Pain intensity was assessed using the Visual Analogue Scale (VAS) at 30, 15, 10, 0, and 60 minutes. Additionally, we compared side effects, response rate, need for additional doses, pain relief, treatment failure, the Side Effects Rating Scale for Dissociative Anesthetics (SERSDA), and the onset of drug effect between the two groups. The data were analyzed using SPSS software. Results: A total of 202 multiple trauma patients were included in the study, with one group receiving ketamine nebulizer and the other receiving intravenous morphine. There were no significant differences in pain intensity between the morphine and ketamine groups at all measured time points (p < 0.05). However, lightheadedness, hot flashes, and chest heaviness were significantly more common in the intravenous morphine group, while hallucinations, irritation of the nasal mucosa, and tremors were significantly more common in the nebulized ketamine group. The onset time of the drug effect was significantly shorter in the nebulized ketamine group compared to the intravenous morphine group (p = 0.030). Conclusion: Nebulized ketamine can be considered a viable alternative to intravenous morphine in emergency trauma patients due to its comparable analgesic effect and faster onset without the complications associated with intravenous morphine.