This book constitutes the refereed proceedings of the 17th International Conference on Principles and Practice of Multi-Agent Systems, PRIMA 2014, held in Gold Coast, QLD, Australia, in December 2014. The conference was co-located with the 13th Pacific RIM International Conference on Artificial Intelligence, PRICAI 2014. The 21 revised full papers presented together with 15 short papers and 2 invited papers were carefully reviewed and selected from 77 submissions. The papers are organized in topical sections on self organization and social networks/crowdsourcing; logic and argumentation; simulation and assurance; interaction and applications; norms, games and social choice; and metrics, optimisation, negotiation and learning.