This book constitutes the refereed proceedings of the 15th International Conference on Formal Engineering Methods, ICFEM 2013, held in Queenstown, New Zealand, in October/November 2013. The 28 revised full papers together with 2 keynote speeches presented were carefully reviewed and selected from 88 submissions. The topics covered are abstraction and refinement, formal specification and modeling, program analysis, software verification, formal methods for software safety, security, reliability and dependability, tool development, integration and experiments involving verified systems, formal methods used in certifying products under international standards, and formal model-based development and code generation.