The prediction of runoff in ungauged basins (PUB) is one of the key challenges of water resources management. A Benchmark Assessment Report is currently being compiled which summarises the state of hydrological predictions for ungauged basins with various runoff signatures. Members of the EUROFRIEND Low Flow and Drought group contribute to one chapter on low flow estimation. In this paper, two major European benchmark studies from the PUB Benchmark Assessment Report on low flow regionalisation are presented. In each study, several competing methods are compared by cross-validation to shed light on the performance of different methods for predicting low flows in ungauged basins. The chapter on low flows is an example of how UNESCO-FRIEND has stimulated international cooperation and has established links with a related international programme (i.e. IAHS-PUB) to help gain knowledge and exchange best practise.