This book constitutes the refereed proceedings of the 7th Workshop on New Frontiers in Quantitative Methods in Informatics, InfQ 2017, held in Venice, Italy, in December 2017. The 11 revised full papers and the one revised short paper presented were carefully reviewed and selected from 22 submissions. The papers are organized in topical sections on networking and mobile applications; applications of quantitative modeling; big data processing and IoT; theory, methods and tools for quantitative analysis.