The conference on Autonomous Agents and Multiagent Systems (AAMAS) is the leading scientific conference for research in autonomous agents and multi-agent systems. The AAMAS conference series was initiated in 2002 as a merger of three highly respected individual conferences: the International Conference in Autonomous Agents, the International Workshop on Agent Theories, Architectures, and Languages, and the International Conference on Multi-Agent Systems. The aim of the joint conference is to provide a single, high-profile, internationally respected archival forum for research in all aspects of the theory and practice of autonomous agents and multi-agent systems. AAMAS 2008 is the seventh conference in the AAMAS series, following enormously successful previous conferences in Bologna, Italy (2002), Melbourne, Australia (2003), New York, USA (2004), Utrecht, The Netherlands (2005), Hakodate, Japan (2006), and Honolulu, Hawai'i (2007). AAMAS 2008 will be held at the Cascais Miragem, Estoril, Portugal . AAMAS 2008 is presented in cooperation with the ACM and AAAI. This is volume 1 of main proceedings of AAMAS 2008 containing a selection of full papers accepted at the conference. Volume 2 with other full papers, volume 3 with short papers, demo papers and extended abstracts of the doctoral mentoring program, as well as a fourth volume for the Industry and Application Track papers, are also available.