This volume contains the proceedings of EWSN 2008, the fifth European Conference on Wireless Sensor Networks, held in Bologna, Italy, during January 30–31 and February 1, 2008.Its scope was the creation of a forum where researchers with different experience and background could discuss cross-layer approaches, novel solutions for specific problems and envisage the future development of wireless sensor networks (WSNs).Out of the 110 papers that were submitted, 23 were selected after a doubleblind peer-review process, leading to an acceptance rate of 21%. Six among the accepted papers included authors from North America, three from Asia, all others from Europe with the exception of one from Australia, and one from Brazil: the conference brought together researchers from almost all corners of the world!