This book constitutes the strictly refereed post-workshop proceedings of the 23rd International Workshop on Graph-Theoretic Concepts in Computer Science, WG'97, held in Berlin, Germany in June 1997. The volume presents 28 revised full papers carefully selected for inclusion in the book from 42 submissions. The papers address a variety of graph-theoretic issues relevant from the computer science point of view such as graph algorithms, cycles, graph decompositions, interconnection networks, local search, graph orderings, graph matching, graph languages, tree-width computation, etc.