This book constitutes the refereed proceedings of the 19th International Conference on Principles and Practice of Multi-Agent Systems, PRIMA 2016, held in Phuket, Thailand, in August 22-26, 2016. The 16 revised full papers presented together with two invited papers, 9 short papers and three extended abstracts were carefully reviewed and selected from 50 submissions. The intention of the papers is to showcase research in several domains, ranging from foundations of agent theory and engineering aspects of agent systems, to emerging interdisciplinary areas of agent-based research.

This book constitutes the thoroughly refereed proceedings of the 9th International Workshops on Coordination, Organizations, Institutions and Norms in Agent Systems, COIN 2013. The workshops were co-located with AAMAS 2013, held in St. Paul, MN, USA in May 2013, and with PRIMA 2013, held in Dunedin, New Zealand, in December 2013. The 18 full papers were carefully reviewed and selected from 28 submissions and are presented together with two invited papers. The papers are organized in topical sections such as coordination, organizations, institutions, norms, norm conflict, and norm-aware agents.