This book constitutes the thoroughly refereed post-conference proceedings of the 18th International Symposium on Logic-Based Program Synthesis and Transformation, LOPSTR 2008, held in Valencia, Spain, during July 17-18, 2008. The 11 revised full papers presented together with one invited talk were carefully reviewed and selected for inclusion in the book. LOPSTR traditionally solicits papers in the areas of specification, synthesis, verification, transformation, analysis, optimization, composition, security, reuse, applications and tools, component-based software development, software architectures, agent-based software development, and program refinement.

Space Invading Systems Code.- Test Data Generation of Bytecode by CLP Partial Evaluation.- A Modular Equational Generalization Algorithm.- A Transformational Approach to Polyvariant BTA of Higher-Order Functional Programs.- Analysis of Linear Hybrid Systems in CLP.- Automatic Generation of Test Inputs for Mercury.- Analytical Inductive Functional Programming.- The MEB and CEB Static Analysis for CSP Specifications.- Fast Offline Partial Evaluation of Large Logic Programs.- An Inference Algorithm for Guaranteeing Safe Destruction.- From Monomorphic to Polymorphic Well-Typings and Beyond.- On Negative Unfolding in the Answer Set Semantics.