BACKGROUND Trauma is the fifth leading cause of death in patients 65 years and older. This study is a comparison of results of Revised Trauma Score (RTS), Injury Severity Score (ISS), and Trauma and Injury Severity Score (TRISS) in prediction of mortality in cases of geriatric trauma. METHODS This is a cross-sectional study of records of 352 elderly trauma patients who were admitted to Pour-Sina Hospital in Rasht between 2010 and 2011. Injury scoring systems were compared in terms of specificity, sensitivity, and cut-off points using receiver operating characteristic curve of patient prognosis. RESULTS Mean age of patients was 71.5 years. Most common mechanism of injury was traffic accident (53.7%). Of the total, 13.9% of patients died. Mean ISS was higher for patients who did not survive. Mean of TRISS and RTS scores in elderly survivors was higher than non-survivors and difference in all 3 scores was statistically significant (p<0.001). Best cut-off points for predicting mortality in elderly trauma patients in RTS, ISS, and TRISS systems were ≤6, ≥13.5, and ≤2, with sensitivity of 99%, 84%, and 95% and specificity of 62%, 62%, and 72%, respectively. CONCLUSIONS TRISS was the strongest predictor of mortality in elderly trauma patients as result of combination of both anatomical and physiological parameters.