This book constitutes the refereed proceedings of the 22nd International Conference on Computer Safety, Reliability and Security, SAFECOMP 2003, held in Edinburgh, UK in September 2003. The 30 revised full papers presented together with two keynote talk abstracts were carefully reviewed and selected from 96 submissions. The papers are organized in topical sections on formal methods, design for dependability, security and formal methods, dependability and performance analysis, dependability of medical systems, fault tolerance, tools for dependable design, dependability of critical infrastructures, hazard and safety analysis, and design for dependability.