The International Workshop on Graph-Theoretic Concepts in Computer Science is one of the most traditional and high quality conferences in Computer Science. PreviousconferenceswereorganizedatvariousplacesinAustria, Germany, Italy, and the Netherlands. The workshop aims at uniting theory and practice by demonstrating how graph-theoretic concepts can be applied to various areas in computer science, or by extracting new problems from applications. The goal is to present recent research results and to identify and explore directions of future research. The workshop is well-balanced with respect to established researchers and young scientists. th The24 InternationalWorkshoponGraph-TheoreticConceptsinComputer Science(WG'98)washeldatSmoleniceCastle, nearBratislava, SlovakRepublic, June 18-20, 1998. It was organized by the Slovak Academy of Computer Science in cooperation with the Department of Computer Science I at RWTH Aachen (Germany) and with Slovak Society for Computer Science. For the ?rst time in its history, WG took place in a country of the former eastern block, in the Slovak Republic. The program committee of WG'98 consisted of: H. Bodlaender, Utrecht (NL) A. Brandst] adt, Rostock (D) M. Habib, Montpellier (F) J. Hromkovi? c, Aachen (D) L. Kirousis, Patras (GR) L. Ku? cera, Praha (CR) A. Marchetti-Spaccamela, Roma (I) E. Mayr, Munc ] hen (D) R. Moehring, Berlin (D) M. Nagl, Aachen (D) H. Noltemeier, Wurzburg ] (D) F. Parisi Presicce, Roma (I) O. Syk ´ ora, Bratislava (SK) G. Tinhofer, Munc ] hen (D) D. Wagner, Konstanz (D) P.