A synthesis of river-monitoring data shows that the average annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean increased by 7% from 1936 to 1999, with an average annual increase of 2.0 ± 0.7 km³/year. This increase corresponds to a 128 km³/year rise in discharge, or about 7% more than when measurements began in the 1930s. Discharge is correlated with changes in the North Atlantic Oscillation and global mean surface air temperature. These changes may have significant implications for ocean circulation and climate. The Arctic is expected to be disproportionately affected by global warming, and may exert strong feedback on global climate. Many linkages between the Arctic system and global climate involve the hydrologic cycle, including atmospheric moisture transport from lower to higher latitudes. This transport is predicted to increase with warming. Both theoretical arguments and models suggest that net high-latitude precipitation increases in proportion to increases in mean hemispheric temperature. Global surface air temperature has increased 0.6°C over the past century. Thus, one might expect that net moisture transport into the pan-arctic drainage basin is already increasing. Arctic river discharge is particularly useful for addressing this question, as it provides an integrative measure of the continental water balance. The pan-arctic drainage covers 22.4 × 10⁶ km², an area about 1.5 times that of the Arctic Ocean. Consequently, the Arctic Ocean is the most land-dominated of ocean basins. Evidence of increasing Arctic river discharge has been reported in several recent publications, with changes most evident during the low-flow period from November through April. However, analyses of trends have emphasized different time periods and areas of the Arctic. Thus, it has been difficult to generalize about temporal trends in discharge to the Arctic Ocean. Discharge records for downstream stations on major North American Arctic rivers extend back only a few decades, whereas gauging of major Eurasian Arctic rivers generally began in the 1930s. The longer records provide the best opportunity for detecting change. Here we identify long-term trends in discharge from major Eurasian rivers to the Arctic Ocean and evaluate their possible links to climate variability. Total river inflow to the Arctic Ocean is dominated by contributions from Eurasia. The six largest Eurasian Arctic rivers drain about two-thirds of the Eurasian Arctic landmass and include three of the largest rivers on Earth. Over the period of record (from 1936 to 1999), aggregate annual discharge from the six largest Eurasian Arctic rivers shows a significant positive trend. The average annual rate of increase was 2.0 ± 0.7 km³/year. Thus, average annual discharge is now about 128 km³/year greater than it was when routine measurements began in the 1930s. This amounts to an approximateA synthesis of river-monitoring data shows that the average annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean increased by 7% from 1936 to 1999, with an average annual increase of 2.0 ± 0.7 km³/year. This increase corresponds to a 128 km³/year rise in discharge, or about 7% more than when measurements began in the 1930s. Discharge is correlated with changes in the North Atlantic Oscillation and global mean surface air temperature. These changes may have significant implications for ocean circulation and climate. The Arctic is expected to be disproportionately affected by global warming, and may exert strong feedback on global climate. Many linkages between the Arctic system and global climate involve the hydrologic cycle, including atmospheric moisture transport from lower to higher latitudes. This transport is predicted to increase with warming. Both theoretical arguments and models suggest that net high-latitude precipitation increases in proportion to increases in mean hemispheric temperature. Global surface air temperature has increased 0.6°C over the past century. Thus, one might expect that net moisture transport into the pan-arctic drainage basin is already increasing. Arctic river discharge is particularly useful for addressing this question, as it provides an integrative measure of the continental water balance. The pan-arctic drainage covers 22.4 × 10⁶ km², an area about 1.5 times that of the Arctic Ocean. Consequently, the Arctic Ocean is the most land-dominated of ocean basins. Evidence of increasing Arctic river discharge has been reported in several recent publications, with changes most evident during the low-flow period from November through April. However, analyses of trends have emphasized different time periods and areas of the Arctic. Thus, it has been difficult to generalize about temporal trends in discharge to the Arctic Ocean. Discharge records for downstream stations on major North American Arctic rivers extend back only a few decades, whereas gauging of major Eurasian Arctic rivers generally began in the 1930s. The longer records provide the best opportunity for detecting change. Here we identify long-term trends in discharge from major Eurasian rivers to the Arctic Ocean and evaluate their possible links to climate variability. Total river inflow to the Arctic Ocean is dominated by contributions from Eurasia. The six largest Eurasian Arctic rivers drain about two-thirds of the Eurasian Arctic landmass and include three of the largest rivers on Earth. Over the period of record (from 1936 to 1999), aggregate annual discharge from the six largest Eurasian Arctic rivers shows a significant positive trend. The average annual rate of increase was 2.0 ± 0.7 km³/year. Thus, average annual discharge is now about 128 km³/year greater than it was when routine measurements began in the 1930s. This amounts to an approximate