The emerging field of nanotechnology has envisioned a great impact in basic and applied research in different areas, leading to the production of materials with novel properties and devices with new or improved performance. Findings in this field have opened new opportunities for active research in different areas such as biomedicine, catalysis, electronics, and cosmetics, among others. With the continuous aim of providing a forum where the latest developments in nanoscience and nanotechnology can be presented and discussed, the XXI International Materials Research Congress held in Cancún, México in August 2012, hosted the Nanostructured Materials and Nanotechnology Symposium. Topics covered include the synthesis of nanostructures and nanocomposites; optical, electrical and structural characterization techniques; modeling of structures and theoretical analysis of properties; carbon based nanostructures and different applications of nanomaterials as in catalysis, biomedicine and sensors development.