This book constitutes the thoroughly refereed post-workshop proceedings of the First International Workshop on Modelling and Simulation for Autonomous Systems, MESAS 2014, held in Rome, Italy, in May 2014. The 32 revised full papers included in the volume were carefully reviewed and selected from 50 submissions, of which 46 were presented at the workshop. They are organized in the following topical sections: unmanned aerial vehicle, distributed simulation, robot system, military application, validation, human-machine communication, gazebo simulator, and algorithm.