This book constitutes the refereed proceedings of the 25th International Conference on Computer Safety, Reliability, and Security, SAFECOMP 2006. The 32 revised full papers were carefully reviewed and selected from 101 submissions. Topical sections include systems of systems, security and survivability analysis, nuclear safety and application of standards, formal approaches, networks dependability, coping with change and mobility, safety analysis and assessment, 6th FP integrated project DECOS, and modelling.