This textbook provides lecturers and, in particular, students of social sciences, humanities, or law with a detailed insight into the topic of international organizations. The text presents the origins and development, goals and principles, organizational structure and financing, as well as the areas of action of nine governmental (UN, AU, ASEAN, EU, OAS, Council of Europe, NATO, OSCE, WTO) and eight non-governmental international organizations (Amnesty International, Human Rights Watch, Greenpeace, WWF, ICRC, Doctors Without Borders, CARE International, Oxfam) in a well-founded, clear, and comprehensible manner. The volume is particularly suitable as a reference work, for preparing presentations and exams, as well as a basis for term papers and theses.