The development and testing of a Web-based GIS e-learning resource is described. This focuses on the application of GIS for siting a nuclear waste disposal facility and the associated principles of spatial decision-making using Boolean and weighted overlay methods. Initial student experiences in using the system are analysed as part of a research project on teaching GIS concepts to large numbers of students with little or no prior GIS experience. Some general thoughts on the utility of Web-based GIS for learning and teaching are presented. Results from the first cohort of 167 undergraduate/postgraduate geography students using the system indicate that students find it easy to use, a useful aid to learning about the issues involved, and a thought-provoking exercise in Internet-based democracy.