Tehran University of Medical Sciences Frontiers in Emergency Medicine 2717-3593 9 2 2025 05 30 e12 e12 Mitra Akhlaghi Department of Forensic Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Alireza Kadkhodaei Legal Medicine Organization, Tehran, Iran. Reihaneh Khabazian Legal Medicine Organization, Tehran, Iran. Elham bazmi Legal Medicine Organization, Tehran, Iran. Mohammad Hossein Sadeghian Department of Forensic Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 2024 09 24 2025 01 13 Objective: Motorcycle-related traffic crashes remain a significant cause of severe injuries and fatalities, particularly in young populations. This study aimed to compare the injury severity and patterns sustained by motorcycle riders and passengers in crashes.  Methods: A retrospective analysis was conducted on motorcycle crash victims, including both riders and passengers, evaluated at the forensic medical organization in Iran from 2020 to 2022. Variables such as injury type, helmet use, and demographic factors were compared. The chi-squared test was applied to categorical variables, with P-values of <0.05 considered significant. The injury severity score (ISS) and the abbreviated injury scale (AIS) were used to assess trauma severity.  Results: Of 214 cases (81.8% male), helmet use was significantly higher among riders than passengers (39.6% vs. 14.8%, P<0.05). Passengers demonstrated a greater risk of severe injury (45.4%) than riders (27.4%, P=0.01). Head injuries were significantly more prevalent among passengers (13%) than riders (5.7%, P=0.019), correlating with lower helmet use among the passengers. Additionally, fractures and dislocations were more common in passengers, while external injuries predominated in riders.  Conclusion: Strengthening helmet regulations for passengers is critical to reducing head trauma. Stricter enforcement of traffic safety measures could significantly mitigate fatalities, especially among novice riders. https://fem.tums.ac.ir/index.php/fem/article/view/1479 https://fem.tums.ac.ir/index.php/fem/article/download/1479/519