This book constitutes the refereed proceedings of the Third International Workshop on Intelligent Virtual Agents, IVA 2001, held in Madrid, Spain in September 2001.The 16 revised full papers and five short papers presented together with two invited surveys were carefully reviewed and selected for inclusion in the book. Among the topics addressed are intelligent agents in education, virtual human societies, virtual agents, animation systems, autonomous avatars, the virtual self, agent societies, Internet agents, mobile agents, collaborative virtual environments, virtual storytelling, interactive improvisational plays, agent-oriented simulation, and 3D agents.