Since 2007, Center of Excellence for High Performance Materials, University of Tehran, has successfully arranged a series of biennial conferences focused on Ultrafine Grained and Nano-Structured Materials. The purpose of these meetings is to allow those interested in the field to get together to present their research in a setting that fosters discussion, collaboration, and advancement in the field. The 5th conference is organized by University of Tehran, Iran. Selected papers presented in this conference will be peer reviewed and published in international journals.