We welcome you to the proceedings of IWQoS 2005 held at the University of Passau, in the beautiful state of Bavaria, Germany. We hope that all attendees enjoyed their time in that ancient and historic city. Quality of Service(QoS) continues to be an important area of research. T- ditionally very focused on the area of networking, it has grown to include mobile applications, wireless environments, 3G and 4G cellular networks, user expe- ence, overlay networks, large-scale systemsand other important areas ofappli- tion. Six full-paper sessions that comprised selected papers of very high quality were devoted to the above mentioned, cutting-edge topics in this volume. We had a fascinating cross-disciplinary program and hope to have seeded conn- tions between di?erent disciplines and between industry and academia. In addition to the reviewed paper sessions, we were pleased to present two inspiring keynote speakers in this year's program: Randy Katz, Universityof California, Berkeley, USA, and Michael Stal, SiemensAG, Munich, Germany. One speaker being from academia and one from industry, re?ected well the balanced view of this workshop. Both keynotes extended the scope of QoS and addressed pressing issues, such as "spam," and leading trends, such as "service orientation," and their relevance to QoS.