Abstract Hydropower fuels the overall societal development by contributing a notable proportion to the whole global power generation. Although much attention has been paid to the development of hydropower, few of them attempted to gather global systematic data and conduct a large-scale review of scientific studies. In such situation, a bibliometric approach is employed in this study to quantitatively evaluate global scientific research on hydropower sustainable development, with a long time span ranging from 1991 to 2012. 434 publications in accordance with the search criteria from Science Citation Index Expanded (SCI-Expanded) database are analyzed statistically, and assessments on research development, current trends, and future directions are conducted in regard to eight categories. By synthetically analyzing the keywords, the dominant hotspots of hydropower sustainable research could be concluded as “Turkey”, “Eco-”, “Small hydro-”, and “Fish”. Along with a comparable number of publications to the United State, the keyword “Turkey” has exhibited a notable increase since 2000, revealing its predominance in the research on the hydropower sustainable development. Increasing attention has also been directed to the prefixes “Small hydro-” and “Eco-” in recent years. The keywords related to fish are identified from the keyword analyses as well, suggesting that the significance of fish studies has been recognized by researchers. Given the trend during the past several years, these topics are likely to become primary research focuses in the coming period.