This volume is the latest of the “Kirchberg-Proceedings”. The previous 11 International Winterschools on Electronic Properties of Novel Materials, all held in Kirchberg, Austria, were devoted to conducting polymers, high temperature superconductors, fullerenes, and carbon nanotubes. Fullerenes and nanotubes are still in the center of interest, but the topic of the school and the proceedings is molecular nanostructures in general. The organizers have attempted to treat carbon nanostructures as a special case of molecular nanostructures, which also include silicon clusters, gold clusters, vanadium oxide tubes, and many others. The Winterschool provides a platform for reviewing and discussing new developments in the field of molecular nanostructures and their applications. Materials discussed include fullerenes, fullerene-derived structures, carbonaceous nanotubes, non-carbonaceous nanotubes, layer by layer systems, molecular clusters, new phases of carbon, endohedral compounds and related materials. The book aims to give an overview of the current status of fullerenes, carbon-nanotubes and related molecular nanostructures. The majority of the contributions present the latest results of experiments and calculations conducted in the field. However, about a dozen contain some degree of instructional material which even newcomers will benefit from.