This study applies environmental criminology and situational crime prevention (SCP) to study successful and unsuccessful assassinations by terrorists. Using these perspectives, a series of hypotheses were devised to understand the situational factors that contribute to successful compared to unsuccessful assassinations. A random sample of roughly 1,000 successful and 1,000 unsuccessful assassination attacks taking place between 2005 and 2014 was acquired from the Global Terrorism Database (GTD). Open source materials were then consulted to supplement the GTD with the creation of new SCP variables. The hypotheses were tested in a binary logistic regression, and additional regression models were created for 4 specific regions (the Middle East & North Africa, South Asia, Southeast Asia, and Sub Saharan Africa). Results indicate support for the application of SCP and environmental criminology to the study of assassinations by terrorists. Specifically, successful assassinations are associated with guardianship, weapon type, target location, terrorist location, attack intensity, and distance. Findings are largely consistent across the different regions, however, the results from each regional model deviated slightly from the full model, indicating that the impact of certain SCP variables on successful assassinations vary by region