Targeted killing refers to a series of measures taken by some governments, including the United States and Israel, over the last decades to assassinate suspects of the act of terror. Since these actions lack any legitimacy from the perspective of international law, the countries involved try to make their intentions legitimate using such titles as a preventive legal defence to survive an imminent attack. There has always been some degree of ambiguity in the legitimacy of a targeted killing. On the one hand, it is important to distinguish between peacetime and wartime because, from the perspective of international law, targeted killing is only considered legitimate during the armed conflict and by observing its legal criteria; on the other hand, it is crucial who is assassinated. That's why some individuals, including official authorities, enjoy immunity due to their position, so competent domestic courts are thought of as the only eligible entities which could bring them on trial, let alone if they are murdered without trial. Also, the killing of General Soleimani is facing charges of political murder, which is prohibited both in international law and in the domestic law of the United States. The present research is a descriptive-analytical study. Considering the U.S. assassination attempt to kill General Qasem Soleimani, this research aimed to study different aspects, legitimacy, and prohibition of targeted killing from the perspective of international law, as well as investigate specific features of that crime.