This book constitutes the refereed proceedings of the 19th International Workshop on Computer Science Logic, CSL 2005, held as the 14th Annual Conference of the EACSL in Oxford, UK in August 2005. The 33 revised full papers presented together with 4 invited contributions were carefully reviewed and selected from 108 papers submitted. All current aspects of logic in computer science are addressed ranging from mathematical logic and logical foundations to methodological issues and applications of logics in various computing contexts. The volume is organized in topical sections on semantics and logics, type theory and lambda calculus, linear logic and ludics, constraints, finite models, decidability and complexity, verification and model checking, constructive reasoning and computational mathematics, and implicit computational complexity and rewriting.