This book constitutes the post-conference proceedings of the 6th International Workshop on Enterprise and Organizational Modeling and Simulation (EOMAS 2010), held at the CAiSE 2010 conference in Hammamet, Tunisia, June 7-8, 2010.The 12 papers presented in this volume were carefully reviewed and selected from 30 submissions. They cover topics like business process management and simulation, organizational modeling and simulation, enterprise architecture and modeling, and workflow systems.