This volume constitutes the thoroughly refereed post-conference proceedings of the 10th International Workshop on Agent-Oriented Software Engineering, AOSE 2009, held in Budapest, Hungary, in May 2009 as part of AAMAS 2009, the 8th International Conference on Autonomous Agents and Multiagent Systems. The 10 revised full papers presented were carefully selected from numerous initial submissions during two rounds of reviewing and improvement. The papers have been organized into three sections on multi-agent organizations, concrete development techniques, and - one step higher - going beyond the...