This article addresses the origins and evolution of international organizations dedicated to international rail transport. From the beginning of rail history, most of the railway networks in Europe were built by numerous private companies, which continuously competed and collaborated with each other within domestic transport as well as international transport. European railway companies made connections across borders based on personal and financial network relationships and established various types of agreements and unions to make international traffic possible. This coalition allowed them to jointly operate member networks, including running direct trains and establishing tariff agreements. Since international transport has grown in size and complexity, international railway organizations have continuously evolved. This study proceeds as follows: the first section outlines the beginnings and development of international rail transport organizations. With the expansion of the rail network in Europe, international cooperation in the field of railways occurred early in the 19th century. This mainly took the form of bilateral or multilateral agreements or even treaties among the States. Initially, these agreements affected the establishment of international organizations. The second section draws out international organizations between the First World War and the Second World War. In the interwar period, the existing organizations continued to expand their scope of activities and new organizations were founded. The third section examines the impact of the Cold War on international rail organizations. During the Cold War, many organizations were established in Western Europe, with active international railway cooperation. In Eastern Europe, a new international organization was established under the influence of the Soviet Union. The fourth section explains changes in international organizations after the Cold War. After the collapse of the Soviet Union, the existing organizations steadily adapted themselves to changes in the political, economic, social, cultural and technological environments. Because of these various changes, new international organizations also emerged.