The purpose of the proposed special issue is to publish selected papers, after peer review, presented in the international conference “Advanced Methods for Flood Estimation in a Variable and Changing Environment”, which was held in Volos, Greece, 24–26 October 2012 (http://www.cost-floodfreq.eu/activities/conf-worksh/advanced-methods-for-flood-estimation-in-a-variable-and-changing-environment ). The conference was part of the activities of the COST Action ES0901 “European Procedures for Flood Frequency Estimation – FloodFreq” (http://www.cost-floodfreq.eu/home). The main objective of the action is to undertake a pan-European comparison and evaluation of methods for flood frequency estimation under the various climatological and geographical conditions found in Europe, and different levels of data availability. A scientific framework for assessing the ability of these methods to predict the impact of environmental change on future flood frequency characteristics (flood occurrence and magnitude) is developed and tested. The aim of the conference is to be a forum for the presentation of the findings of the action as well as research from scientists/engineers, not affiliated with the action, from Europe and to initiate discussion on the flood estimation and research presented at the conference as a set of guidelines for professionals involved in flood management in Europe. The papers, presented in the session, cover a wide range of topics such as statistical methods for flood frequency estimation, flood frequency analysis using rainfall-runoff methods, regional flood frequency analysis, predicting design floods in ungauged basins, analysis of historical floods, predicting and adapting to flood hazard and risk in a changing environment, statistical downscaling methods for projection of hydrological extremes, and risk-based design for flood management in a nonstationary environment.