Terrorism-related deaths have fallen year after year since peaking in 2014, and whilst the coronavirus disease 2019 (COVID-19) pandemic has disrupted terrorist organizations capacity to conduct attacks and limited their potential targets, counter-terrorism experts believe this is a short-term phenomenon with serious concerns of an escalation of violence and events in the near future. This study aims to provide an epidemiological analysis of all terrorism-related mass-fatality events (>100 fatalities) sustained between 1970-2019, including historical attack strategies, modalities used, and target selection, to better inform health care responders on the injury types they are likely to encounter. The Global Terrorism Database (GTD) was searched for all attacks between the years 1970-2019. Attacks met inclusion criteria if they fulfilled the three terrorism-related criteria as set by the GTD codebook. Ambiguous events were excluded. State-sponsored terrorist events do not meet the codebook's definition, and as such, are excluded from the study. Data analysis and subsequent discussions were focused on events causing 100+ fatal injuries (FI). In total, 168,003 events were recorded between the years 1970-2019. Of these, 85,225 (50.73%) events recorded no FI; 67,356 (40.10%) events recorded 1-10 FI; 5,791 (3.45%) events recorded 11-50 FI; 405 (0.24%) events recorded 51-100 FI; 149 (0.09%) events recorded over 100 FI; and 9,077 (5.40%) events recorded unknown number of FI.Also, 96,905 events recorded no non-fatal injuries (NFI); 47,425 events recorded 1-10 NFI; 8,313 events recorded 11-50 NFI; 867 events recorded 51-100 NFI; 360 events recorded over 100 NFI; and 14,130 events recorded unknown number of NFI. Private citizens and property were the primary targets in 67 of the 149 high-FI events (100+ FI). Of the 149 events recording 100+ FI, 46 (30.87%) were attributed to bombings/explosions as the primary attack modality, 43 (28.86%) were armed assaults, 23 (15.44%) hostage incidents, two (1.34%) were facility/infrastructure attacks (incendiary), one (0.67%) was an unarmed assault, seven (4.70%) had unknown modalities, and 27 (18.12%) were mixed modality attacks. The most common attack modality causing 100+ FI was the use of bombs and explosions (30.87%), followed by armed assaults (28.86%). Private citizens and properties (44.97%) were most commonly targeted, followed by government (6.04%), businesses (5.37%), police (4.70%), and airports and aircrafts (4.70%). These data will be useful for the development of training programs in Counter-Terrorism Medicine (CTM), a rapidly emerging Disaster Medicine sub-specialty.