The delineation of the world’s international river basins has not been undertaken by any formal body since 1978. Researchers with the Transboundary Freshwater Dispute Database have attempted to fill this void through the 1999 Register, with online updates and currently with the present study. This current register delineates 310 international river basins, reflecting changes in political boundaries and increased data quality. These basins are shared by 150 countries and disputed areas, cover 47.1% of the Earth’s land surface and include 52% of the world’s population. This paper lists all international river systems, their basin areas, their riparian states and their respective territorial percentages.