This volume contains the proceedingsof EWSN 2009, the 6th European Conf- ence on Wireless Sensor Networks. The conference took place in Cork, Ireland during February11-13,2009. The aim ofthe conferencewasto discussthe latest research results and developments in the ?eld of wireless sensor networks. EWSN received a total of 145 full paper submissions of which 23 were - lectedfor publicationandpresentation, yielding anacceptancerateofjust under 16%. Paper submissions were received from 36 di?erent countries in all parts of the world. EWSN adopted a double-blind review process, where the...