This book constitutes the refereed proceedings of the 10th International Conference on Intelligent Virtual Agents, IVA 2010, held in Philadelphia, Pennsylvania, USA, in September 2010. The 18 revised full papers and 34 revised short papers presented together with 26 poster papers, 3 keynote talks, and 3 invited papers were carefully reviewed and selected from 93 submissions. The papers are organized in topical sections on Behavior Modeling, Gesture and Expression, Backchannels and Simulation, Personality, Interaction Strategies, Emotion as well as User Studies