The 5th edition of the ‘Hydrology Days’ of the Italian Hydrological Society was held in Perugia, Italy, 6–8 October 2015, to provide a joint forum of hydrologists and a broad range of stakeholders for commenting and discussing on ‘River basin hydrology and natural hazards: monitoring, prediction and prevention’. A total of 58 abstracts were presented at the workshop. The 2½-day conference was organized by the ‘Hydrology Group’ of the Research Institute for Geo-Hydrological Protection (National Research Council of Italy) in collaboration with the Italian Hydrological Society, the Tiber River Basin Authority and the professional association of Engineers of Perugia. Specifically, the Italian Hydrological Society (SII-IHS) was founded in 2009 to foster progress, enhancement and dissemination of hydrological sciences in Italy, including all aspects related to water resources systems management and possible interaction with human activity. In this perspective, one of the main objectives of the Association is to stimulate interdisciplinary collaboration among academia, research institutes, institutional stakeholders and private operators.