This book constitutes the proceedings of the 16th International Conference on Practical Applications of Agents and Multi-Agent Systems, PAAMS 2018, held in Toledo, Spain, in June 2018. The 20 regular and 19 demo papers presented in this volume were carefully reviewed and selected from 57 submissions. They deal with the application and validation of agent-based models, methods, and technologies in a number of key applications areas, such as: energy and security; engineering and tools; evaluation and ethics; negotiation and organisations; personalization and learning; simulation applications; simulation platforms; social networks and humans. The book also contains two invited talks in full paper length.