This book constitutes the thoroughly refereed post-workshop proceedings of the 13th International Workshop on Formal Methods for Industrial Critical Systems, FMICS 2008, held in L'Aquila, Italy, in September 2008 - colocated with ASE 2008, the 23rd International Conference on Automated Software Engineering. The 14 revised full papers presented together with the abstracts of 3 invited presentations and 2 short presentations introducing the panel were carefully selected from 36 initial submissions. The papers strive to promote research and development for the improvement of formal methods and tools for industrial applications. They cover topics such as model checking, testing, software verification, real-time performance, and industrial case studies.