Geographical Information Systems (GISs) are becoming more prevalent for retailers in their use for both day-to-day and strategic long-term decision-making. Given the array of internal and external databases they use, as well as the amount of organizational development, systems implementation is a most opposite picture of how GIS support retailing decision-making. This chapter presents the results of in-depth case studies, reflecting upon the GIS implementation experiences of a key UK food retailer, Highway Stores PLC. The company is one of the strongest contenders in UK food retailing (fourth in rank). More sites throughout the country are being explored and considered for development, and the implementation of GIS has supported Highway in determining locations where new stores can be built-up that fascinate new customers and ensure that existing customers are retained.