This book constitutes the refereed proceedings of the International Central and European Conference on Multi-Agent Systems, CEEMAS 2003, held in Prague, Czech Republic in June 2003. The 58 revised full papers presented together with 3 invited contributions were carefully reviewed and selected from 109 submissions. The papers are organized in topical sections on formal methods, social knowledge and meta-reasoning, negotiation, and policies, ontologies and languages, planning, coalitions, evolution and emergent behaviour, platforms, protocols, security, real-time and synchronization, industrial applications, e-business and virtual enterprises, and Web and mobile agents.