Symposium R, “Nanostructured Semiconductors and Nanotechnology” was held April 1–5, 2013, at the 2013 MRS spring meeting in San Francisco, California. The aim of the symposium was to review present and future trends of research on nanostructured semiconductors from fundamental issues of synthesis (epitaxy, nanofunctionalization, and self-assembly) to emerging applications in advanced devices (nanoelectronics, photovoltaics, nanophotonics, etc.).