These proceedings contain the papers selected for presentation at the 5th edition of the International Workshop on Web and Wireless Geographical Information Systems, held in December 2005, in Lausanne, Switzerland. The aim of the series of annual W2GIS workshops is to provide an up-to-date review of advances on recent devel- ment and research results in the field of web and wireless geographical information systems. It follows the successful 2001, 2002, 2003, 2004 editions, held in Kyoto, Singapore, Rome and Seoul, respectively. It now represents a young but rapidly - turing research community. In its 5th year, W2GIS reached new heights of recognition as a quality workshop for the dissemination and discussion on latest research and development achievements in the domain. The number of papers received for this workshop demonstrates the growing interest of the research community. There were 70 submissions from 17 countries, many of them of excellent quality and most of them very related to the t- ics of the workshop. Each paper receives three reviews. Based on these reviews, 25 papers were selected for presentation and inclusion in the proceedings. The accepted papers cover a wide range of topics from the Semantic Web, Web personalization, contextual representation and mapping to querying in mobile environments, to mobile networks and location-based services. We had the privilege of having a distinguished invited talk "The next revolution: Peer-to-Peer discovery on mobile devices" by Ouri Wolfson, University of Illinois at Chicago, USA.