This book constitutes the thoroughly refereed post conference proceedings of the 5th International Andrei Ershov Memorial Conference, PSI 2003, held in Akademgorodok, Novosibirsk, Russia in July 2003. The 55 revised full papers presented were carefully reviewed and selected from 110 submissions during two rounds of evaluation and improvement. The papers are organized in topical sections on programming, software engineering, software education, program synthesis and transformation, graphical interfaces, partial evaluation and super compilation, verification, logic and types, concurrent and distributed systems, reactive systems, program specification, verification and model checking, constraint programming, documentation and testing, databases, and natural language processing