ThesearetheproceedingsoftheGermanconferenceonMultiagentSystemTe- nologies(MATES2003),whichwasthe?rstconferenceorganizedbytheGerman specialinterestgrouponDistributedArti?cialIntelligencetopromotethetheory and application of agents and multiagent systems. Its goals were to cover the whole range from the theory to applications of agent and multiagent technology and re?ect the national and international state of the art. The conference p- vided an excellent interdisciplinary forum for both researchers and members of business and industry to present and discuss the latest advances in theoretical work on and prototyped or ?elded systems of intelligent agents. Building on the sequence of agent-related events in Germany in the past, such as VDI 1998 (Chemnitz), VertIS 2001 (Bamberg), and KI 2002 (Aachen), MATES 2003 was exclusively devoted to agents and multiagent systems, and the cro- fertilization between agent theory and application. In addition, it built on the success of the past international workshop on Agent Technology and Software Engineering (AgeS 2002), and the international symposium on Multiagent Systems,LargeComplexSystems,andE-Businesses(MALCEB2002).M ATES 2003 was co-located with the fourth international Net.ObjectDays conference in an exciting event held in Erfurt during September 22-24. The MATES 2003 conference featured a sequence of regular and invited talks of excellence given by leading experts in the ?eld. Among these were two k- notes, an invited talk and 18 paper presentations selected from 49 submissions.