Terrorism is one of the most difficult and the most inhuman criminal offences. Although its roots go far back into the past, as a way of struggle for the achievement of political objectives, it was more massive in the 20th century, and it is expected that it will experience the true expansion in the future. This phenomenon is the subject of interest and study of many sciences, primarily political, security and legal ones. Since terrorism represents one of the greatest threats to the security of the state and society nowadays, the authors of this paper have studied its criminal and legal aspect. The first part of the paper is focused on the conceptual definition and elements of the criminal offence of terrorism in certain comparative crimina...