This overview highlights very recent achievements and new trends in one of the most active and developing fields in modern materials science: the production of bulk ultrafine-grained (UFG) materials using severe plastic deformation (SPD). The article also summarizes the chronology of early work in SPD processing and presents clear and definitive descriptions of the terminology currently in use in this research area. Special attention is given to the principles of the various SPD processing techniques as well as the major structural features and unique properties of bulk UFG materials that underlie their prospects for widespread practical utilization.