R-ArcticNet is a comprehensive river discharge database that covers the entire pan-Arctic drainage system. The collection comprises data from 9138 gauges and contains monthly river discharge data extending from the 1890s (for four Canadian and five Russian gauges) through the early 1990s, but the majority of data was collected between 1960 and 2001. The pan-Arctic drainage region covers a land area of approximately 21 million km2 and drains into the Arctic Ocean as well as Hudson Bay, James Bay, and the Northern Bering Strait. The collection also includes the Yukon and Anadyr River basins. Most of the drainage basins in the database are greater than 15,000 km2; however, the collection includes all available gauge data from Canada and Russia. Data from gauges measuring large drainage areas are of greatest interest to the regional, continental, and global-scale scientific community for modeling purposes. Individual station data are accessible through a graphical interface, or as tab-delimited ASCII text. Tab-delimited ASCII data are also compiled by hydrological region and as a single file for the complete data set.