The spread of Internet connectivity and advancement of computer hardware increases the power of information technologies to perform practical services in many areas of our everyday life. Agent technologies play essential roles in the design of service-oriented systems such as computer-mediated collaboration, education and training, electronic commerce, information retrieval, and data mining.Agents and multiagent systems also provide a new way of thinking--conceptualizing performance elements as autonomous changes the paradigm for analyzing problems, designing systems, and dealing with complexity, distribution, and interactivity. Concept of agents and multiagent architecture are shaping landscapes of basic research areas including social simulation, games, pervasive and ubiquitous computing, robotics, and user interfaces.The Autonomous Agents and Multiagent Systems (AAMAS) conference series brings together researchers from around the world to share the latest advances in the field. It was initiated in 2002 as a merger of three highly successful related events: the International Conference on Autonomous Agents (AGENTS), the International Conference on Multi-Agent Systems (ICMAS), and the International Workshop on Agent Theories, Architectures, and Languages (ATAL). The AAMAS conference series provides a single, high-profile forum for research in the theory and practice of autonomous agents and multiagent systems. AAMAS 2002, the first of the series, was held in Bologna, followed by AAMAS 2003 in Melbourne, AAMAS 2004 in New York, and AAMAS 2005 in Utrecht. AAMAS 2006 is held in Hakodate, Japan.The five-day event consists of 6 tutorials, 32 workshops, a main conference track, a separate industry paper track with 15 papers, demonstration sessions with 17 demonstrations, an exhibition, and a doctoral mentoring program with 24 students. These and other conference elements are the result of great efforts on the part of many dedicated volunteers. We are grateful to all the AAMAS-06 conference officials and those who worked with them to put together such a successful research meeting.AAMAS 2006 received 553 submissions for the main conference. Each paper was reviewed by at least three program committee members (guided by a senior program committee member). 127 papers were accepted as full 8-page papers, and an additional 123 were accepted as short 3-page papers (acceptance rates of 23.0% for full papers and 45.2% overall).Several innovations were added to this year's conference program and review process. In order to make the review process more interactive, authors were given the opportunity to respond to their reviews prior to the discussion phase and final decisions. In many cases, the reviews, and sometimes the decisions, were altered as a result. In addition, we introduced awards for "best program committee member" and "best senior program committee member" in recognition of the exceptional time and effort contributed by our program committee.At the conference itself, for the first time, the emphasis was on poster presentations as the main form of technical exchange. All accepted papers were presented at poster sessions, with just about half of the full papers presented orally in two parallel tracks. The oral presentations were chosen primarily so as to provide a broad representative of the accepted papers. The goal of this format was to allow for more focused oral sessions while maximizing the opportunity for one-on-one detailed technical exchanges at the posters.