In both the Cooum River and Chennai slums projects the use of GIS was informed by an understanding of social and political implications of the use of the technology. GIS was more prominent in the Cooum research, and was kept in the background in work with slum dwellers. However, in both programs it was subsumed in a collaborative process that allowed stakeholders to express their versions of reality, and their visions for a desirable and feasible future. The efficacy of the process was important, more so than the scientific rigour of the application of GIS to the problem. We argue that this is an appropriate and useful role for GIS that avoids spatial and social marginalization in spatial planning and environmental management. On the other hand, while the potential in India for application for web-based GIS to support public participation is improving, this would only be appropriate in contexts where all groups have the capabilities and resources to access and use the technology, or when multiple means (beyond GIS) are employed to ensure participation of all relevant stakeholders