This book constitutes the thoroughly refereed post-conference proceedings of the 7th International Conference on Fundamentals of Software Engineering, FSEN 2017, held in Tehran, Iran, in April 2017. The 16 full papers presented in this volume were carefully reviewed and selected from 49 submissions. The topics of interest in FSEN span over all aspects of formal methods, especially those related to advancing the application of formal methods in software industry and promoting their integration with practical engineering techniques.