Materials research is a field of growing relevance for innovative nuclear systems, such as Generation IV reactors, critical and sub-critical transmutation systems and fusion devices. For these different systems, structural materials are selected or developed taking into account the pecificities of their foreseen operational environment. Since 2007, the OECD Nuclear Energy Agency (NEA) has begun organising a series of workshops on Structural Materials for Innovative Nuclear Systems (SMINS) in order to provide a forum to exchange information on current materials research programmes for different innovative nuclear systems. These proceedings include the papers of the second workshop (SMINS-2) which was held in Daejon, Republic of Korea on 31 August-3 September 2010, and hosted by the Korea Atomic Energy Research Institute (KAERI).