This book constitutes the refereed proceedings of the 15th International Conference on Product-Focused Software Process Improvement, PROFES 2014, held in Helsinki, Finland, in December 2014. The 18 revised full papers presented together with 14 short papers were carefully reviewed and selected from 45 initial submissions. The papers are organized in topical sections on agile development, decision-making, development practices and issues, product planning, and project management.