Introduction: Injuries cause high rates of mortality and harm to millions of people annually. Objective: The aims of this study were to assess some characteristics of hospitalized trauma patients and determine the variables which were associated with increased rates of mortality. Methods: Data were extracted from the National Trauma Registry of Iran (NTRI) data bank. Among all trauma patients admitted to Sina Hospital, those who had one of the following were registered in the NTRI: hospitalization for more than 24 hours, death less than 24 hours in the hospital, and transferring from the intensive care unit (ICU) of another hospital. Recorded data relating to the interval between 24 July 2016 and 10 October 2019 were analyzed. Results: A total number of 3430 patients were studied, of whom 78 (0.02%) did not survive. The mean age of survivors was 38.4 (±18.5) and it was 58.1 (±23.7) for non-survivors (p<0.001). The mean Glasgow coma scale (GCS) of survivors was 14.9 (±0.7) and it was 11.7 (±4.4) for non-survivors (p<0.001). The most important predictors of death were ICU admission (OR 4.31; 95% CI 1.65-11.26) and not having surgical operation (OR 6.08; 95% CI 2.30-16.03). The injuries with higher injury severity score (ISS) had higher risks of death (OR 1.20; 95% CI 1.06-1.36). Conclusions: In this study, Road Traffic Crashes (RTCs) were the main cause of injuries. The elder age, lower GCS score, ICU admission, higher ISS and not having surgical operation were the worst factors of death. More studies are needed to reveal other prognostic factors of fatal injuries.