Volume is indexed by Thomson Reuters CPCI-S (WoS).The development of materials designed for application in extreme environments is a very active field of research. In recent years, it has been realized by the materials science community that solutions to demanding applications in different fields can be identified by implementing common materials concepts. Research effort and technological development, driven by application requirements, are now a bridge between apparently separate communities. As first realized by the European Integrated Project "ExtreMat - New Materials for Extreme Applications", common materials solutions are now being sought and found in the fields of thermal management materials, protective materials, radiation-resistant materials, bonding and interfaces, as well as advanced materials characterization and application-oriented testing. This special collection is divided into: I. Overview; II. Protection Materials; III. Heat Sinks; IV. Bonding and Interfaces; V. Radiation-Resistant Materials; VI. Advanced Materials Characterization and Testing.It provides incomparable coverage of the current state of the art. The 58 papers in this collection were selected from those presented during the 1st International Conference on New Materials for Extreme Environments held in San Sebastian, Spain, in June 2008. The purpose of the conference was to unite materials researchers to discuss materials solutions in the areas of nuclear fission, advanced nuclear fission, electronics, space, and others. The general topics reflect those discussions and include: protection materials, heat sinks, bonding and interfaces, radiation resistant materials, and advanced materials characterization and testing. Editors are Linsmeier and Reinelt, for whom no background information is given.