This book constitutes the refereed proceedings of the 6th International Symposium on Self-Stabilizing Systems, SSS 2003, held in San Francisco, CA, USA, in June 2003. The 15 revised full papers presented were carefully reviewed and selected from 27 submissions. The papers address self-stabilization issues for various types of systems and software including communication protocols, sensor networks, biological systems, and directed networks; several new algorithms are presented.