This book constitutes the refereed proceedings of the 5th International Workshop on Web and Wireless Geographical Information Systems, W2GIS 2005, held in Lausanne, Switzerland in December 2005. The 25 revised full papers presented were carefully reviewed and selected from 70 submissions and cover a wide range of topics from web semantic and personalization, contextual representation and mapping to querying in mobile environment, to mobile networks and location-based services. The papers are organized in topical sections on mobile GIS and LBS, mapping and representation issues in Web and mobile GIS, mobile networks, querying in a mobile environment, context and personalization issues in Web and mobile GIS, Web GIS, and modeling for Web and mobile GIS.