Materials and Methods: This descriptive-analytical study was conducted in Imam Reza hospital in Tabriz with the participation of 1000 patients by random sampling during 2019. Demographic data and data related to trauma (during hospitalization and after discharge) were obtained from patients" medical records. Finally, data were analyzed in SPSS (version 20) using χ² and logistic regression tests.

Results: The type of the accident was significantly associated with damage to the central nervous system (CNS) and the musculoskeletal system (P = 0.001 and P = 0.003, respectively). Based on the evaluation of patients who came for examination for the second time, it was observed that 22.4% of cases with injuries were not diagnosed during hospitalization. Motorcycle and pedestrian accidents were significantly associated with failure to diagnose in the hospital, and age, motor accident, and winter variables were significantly contributed to the lack of diagnosis.

Conclusions: Orthopedic injuries (upper limbs are much more common than lower limbs) are the most common injuries that are not diagnosed in hospitalized patients with multiple trauma. These injuries are more prevalent among individuals aged 5-30 years old who have been involved in car accidents in the winter.