This book constitutes the refereed proceedings of the 13th International Conference on Fundamental Approaches to Software Engineering, FASE 2010, held in Paphos, Cyprus, in March 2010, as part of ETAPS 2010, the European Joint Conferences on Theory and Practice of Software. The 25 papers presented were carefully reviewed and selected from 103 submissions. The volume also contains one invited talk. The topics covered are model transformation, software evolution, graph transformation, modeling concepts, verification, program analysis, testing and debugging, and performance modeling and analysis.