The last decade has seen a rapid development and growing importance in the application of nuclear physics methods to material sciences. It is a general desire to understand modern material problems on a microscopic scale, which, due to their inherent microscopic nature, made nuclear techniques highly suitable tools for basic and applied research in this field. The Advanced Study Institute on "Nuclear Physics Applications on Ma­ terials Science" brought together scientists active in different but closely re­ lated fields to review and discuss selected topics of bulk properties of metals, semiconductors and insulators as well as properties of surfaces, interfaces and thin films. Most of the excellent lectures and oral presentations of the School are collected in part I of the present volume, while extended abstracts of scientific work presented as posters are added in part II. The pleasant site of the ASI at Viana do Castelo and the northern province of Portugal, Alto Minho, provided the stimulating atmosphere for an in­ spiring School. Many people contributed to the scientific and social success of the institute. Thanks are especially due to the members of the local organizing committee, N. Ayres de Campos, M. Fernanda da Silva, A. Pedroso de Lima and my co-director J. Carvalho Soares. His permanent involvement in preparing and realization of the ASI was essential for this memorable School.