This volume contains a selection of the papers presented at the 10th Inter- tional Workshop on Multi-Agent-Based Simulation (MABS 2009), a workshop co-located with the 8th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2009),which was held during May 10-15, 2009, in Budapest, Hungary. The MABS Workshops Series continues to representan important event that brings together researchers from the multi-agent systems community and the social simulation one. There were 43 submissions for the 2009 edition, each one reviewed by at least three Programme Committee members, and 16 were - cepted for presentation during the workshop. All of them underwent a second review phase, and 12 papers were selected and are collected here, grouped into four general thematic areas. We would like to thank all the authors who considered MABS as a venue to share their work and all those who attended the workshop for their active participation and lively discussion. March 2010 Gennaro Di Tosto H. Van Dyke Parunak Organization The 10th International Workshop on Multi-Agent-Based Simulation (MABS 2009) was organized by the Institute of Cognitive Sciences and Technologies - CNR, Italy, and NewVectors division of TechTeam Government Solutions Inc., MI, USA. Gennaro Di Tosto enjoyed funding from the European Science Fo- dationunderthe EUROCORESinitiative"TECT:the EvolutionofCooperation and Trade". | Multi-agent-based Simulation X by Gennaro Di Tosto, Paperback | Indigo Chapters