Although everyone recognizes communication as a central concept in mul- agents, many no longer see agent communication as a research topic. Unf- tunately there seems to be a tendency to regard communication as a kind of information exchange that can easily be covered using the standard FIPA ACL. However, the papers in this volume show that research in agent communication is far from ?nished. If we want to develop the full potential of multi-agent s- tems, agent communication should also develop to a level beyond parameter or value passing as is done in OO approaches In this book we present the latest collection of papers around the topic of agentcommunication.Thecollectioncomprisesofthebestpapersfromtheagent communication workshops of 2005 and 2006, enriched with a few revised agent communication papers from the AAMAS conference. Due to some unfortunate circumstances the proceedings of the 2005 workshop were delayed, but it gave us the opportunity to join the best papers of the 2006 edition to this volume. Together these papers give a very good overview of the state of the art in this areaofresearchandgiveagoodindicationofthetopicsthatareofmajorinterest at the moment.