This book constitutes the refereed proceedings of the 5th Kurt Godel Colloquium on Computational Logic and Proof Theory, KGC '97, held in Vienna, Austria, in August 1997.The volume presents 20 revised full papers selected from 38 submitted papers. Also included are seven invited contributions by leading experts in the area. The book documents interdisciplinary work done in the area of computer science and mathematical logics by combining research on provability, analysis of proofs, proof search, and complexity.