The article analyzes terrorism as a threat to global security. It was emphasized that this is a historically changeable, multi-faceted, dynamic phenomenon that manifests itself in various forms. Being a war with the state and its structures, a war that does not require resources and a tragic one with consequences. Although the issue of terrorism is the subject of numerous studies and analyzes, experts in this field often focus solely on identifying the main premises triggering the phenomenon under consideration. On the other hand, considerations on terrorism lack an in-depth analysis or an attempt to systematize the sources of terrorism. Hence, the authors of the article notice the need to create a model of the sources of terrorism. In the era of growing conflicts, ethnic, ideological and political tensions, terrorism began to take new forms and became a way to solve the existing problems. The effectiveness of actions taken by terrorist groups largely depends on the funds obtained for this purpose. It is worth noting that terrorist activity is a threat not only to the life and property of individual individuals, and being a fundamental issue of the present world, it can threaten the social order, international relations, and with the use of mass extermination measures, the literal existence of mankind. As a result of all this, the world has been forced to cooperate on a large scale, as terrorists can only be fought through the rapid exchange of information. It is also advisable to cooperate in the field of law as well as to exchange technology. The real method of fighting terrorism is to change the economic systems in the world, as well as create the possibility of a decent life for a quarter of humanity, and also education. To this end, it is necessary to mobilize all citizens around the world. Besides, one should go to the roots of the terrorism phenomenon, and not just "cure" its signs. In today's world, every country must be careful, because there is no guarantee of security in the future and it is difficult to predict when the next terrorist attack will occur. Also Poland, which has so far been free from direct terrorist threats, should be prepared for possible threats from terrorists. In the fight against the phenomenon of terrorism, the Republic of Poland acceded to almost all conventions of the United Nations relating to counteracting this phenomenon. Polish legislation, specifically the criminal code, also includes provisions that apply to terrorism. In addition, we have a number of legal acts, such as the Act on the principles of use or stay of the Armed Forces of the Republic of Poland outside the state, which contain in their content instructions relating to counteracting the phenomenon of terrorism or its aspects. Concluding the considerations on terrorism, it should be emphasized that one should take into account the expansion of this phenomenon, because terrorist groups are not only better organized, but also use more and more radical tools. Therefore, it is important to continue to engage in the subject matter presented in order to avoid severe consequences that may lead to downplaying the topic of terrorism as a threat to global security.