The International Criminal Court (the ICC) was established in order to combat the most serious crimes of concern to the international community as a whole. International terrorism is one the concerns of the international community. It is also stated by the Rome Statute of International Criminal Court that exercising its criminal jurisdiction over those responsible for international crimes is the duty of every State. Moreover, the Rome Statute emphasizes that the International Criminal Court is complementary to national criminal jurisdictions. The focus of this book is on the question of whether the crime of international terrorism should be added into the Rome Statute as an international crime. Due to fact that international terrorism has risen dramatically recently, the question of whether perpetrators of international terrorism committed by non-state actors can be investigated and prosecuted by the ICC has risen. In order to answer the question, this study has focused on main topics of adding the crime of international terrorism into the Rome Statute. What the obstacles to add the crime into the Statute are and the works on adding the crime into the Statute have been explained. Moreover, the problem of defining terrorism as the main obstacle and what makes a crime an international crime have been studied in detail. The question of whether or not perpetrators of international terrorism committed by non-state actors can be investigated and prosecuted under the core crimes listed in the Rome Statute has been addressed. The study had been concluded with some recommendations