This paper discusses the challenges to expanding successful, small-scale urban upgrading initiatives in developing countries, using empirical data from the Slum Networking Project (SNP) in Ahmedabad, India. Despite demonstrated success in providing infrastructure and community development services in 27 slum communities, the SNP has had difficulty expanding its activities beyond this small proportion of the city's 2,431 low-income neighbourhoods. Our case analysis suggests that it is neither insufficient funding nor a lack of political will – both of which are regularly identified as reasons why successful upgrading programmes are not scaled up – that has impeded progress in the Ahmedabad case. Instead, a mismatch between the bundle of services offered by the Municipal Corporation and the priorities of slum households, along with the terms of the partnership between the corporation and the SNP's NGO partners, are among the principal explanations for the SNP's slow rate of expansion.