The workshop Mechanics of Materials , organised by Reinhold Kienzler (Bremen), David L. McDowell (Atlanta) and Ewald A. Werner (München) was held January 22nd–January 28th, 2006. The workshop attracted some 40 participants with a wide geographic spread. Special attention was devoted to increasing the participation of younger members of the related research community. Mechanics of Materials is a broad, interdisciplinary subject that focusses on the intersection of Applied Mathematics, Continuum Mechanics, Material Physics and applications. To address important, emerging topics related to these interdisciplinary areas, several themes were pursued in distinct sessions, each with keynote addresses and extended discussions. The following main topics were treated: Although these fields appear to be quite unconnected, certain physical properties and numerous mathematical approaches were identified as common structures. This includes basic balance and conservation laws as well as variational principles for establishing and solving the evolving partial differential equations. Bridging scales from electrons to macroscopic structures by various consistent methods we were able to arrive at a more complete picture of modelling material behavior and the associated mathematical challenges. The unique atmosphere at the Institute offered an extraordinary opportunity for intense, amiable exchange of currently emerging, detailed and conceptual ideas. The significant amount of time devoted to fruitful discussion is certainly an element that made this meeting in Oberwolfach distinct from other outstanding technical venues. Many new collaborative relationships were initiated. The following abstracts very well summarize both the keynote lectures and the additional contributions to the discussion. It was our great pleasure to celebrate during an informal gathering the 50th anniversary of Horst Lippmann as participant, organizer and long-term intellectual contributor to many Oberwolfach workshops.