The author defines the following: terrorist act; terrorism; ecological terror; terrorist threats; illegal use of terror; terrorist acts in internal and international law. The article discusses terrorism in light of Polish and European law and ecological safety and terrorism (eco-terrorism). Issues o f ecological safety in Europe were addressed in Helsinki in 1975 at the meeting of nations participating in the Conference on Safety and Co-operation in Europe. In the twenty-first century, the general regulations regarding fighting terrorism are applied to ensure ecological safety. Specifically, this refers to the European convention on fighting terrorism laid out in Strasbourg on January 27, 1977 under the auspices of the Council of Europe. The author addressed the issue of actions taken by radical ecologists within the framework of the activities of non-governmental ecological organizations. Actions of a terrorist character undertaken at sea are also discussed. Establishing a contiguous marine coastal zone is an effective method for fighting terrorism.