Injuries caused by terrorism attacks are one of the urgent problems of the society and the health system. In this work, we aimed to assess the injury severity score (ISS) and trauma injury severity score (TRISS) in Tunisian military combatants injured during terrorism attacks. A total of 153 victims of terrorism admitted to the Military Hospital of Tunis between January 2012 and January 2017 were included. Among them, 107 survived and 46 died (43 victims died at the terrorist attack scene and 3 died in the hospital). All dead patients were autopsied. Injury severity scores and TRISSs were then calculated by 2 professors in the anesthesia-resuscitation department, and the agreement level was assessed using the Bland and Altman curve. We obtained a strong agreement between the 2 experts when assessing the TRISS and ISS. Using the Bland and Altman curve, an agreement between the 2 experts was obtained between 0 to 40 and 60 to 75 for the ISS and between 0 to 25 and 75 to 100 for the TRISS. Moreover, we detected a high level of ISS and TRISS, especially in deceased victims compared to survivors (P <.001). To predict mortality, we revealed by the receiver operating characteristic curve high sensitivity and specificity (more than 90%) before day 28 of hospital stay as well as for ISS and TRISS. Regarding the mechanism of injury, patients injured by gunshot have higher ISSs and TRISSs than those injured by explosion (P < .001). Injury severity scores and TRISSs showed a high reliability to predict the mortality rate in Tunisian victims of terrorism.