This book constitutes the revised and selected papers from the 6th International Workshop on Engineering Multi-Agent Systems held in Skholm, Sweden, in July 2018, in conjunction with AAMAS 2018. The 17 full papers presented in this volume were carefully reviewed and selected from 32 submissions. The book also contains a state-of-the-art paper that reflects on the role and potential of MAS engineering in a number of key facets. The papers are clustered around the following themes: programming agents and MAS, agent-oriented software engineering, formal analysis techniques, rational agents, modeling and simulation, frameworks and application domains.