<p>In line with global trends, there has been a significant increase in urban climate action plans in India. There is growing literature on the implementation gap of global and national-level climate action; however, much less on the implementation of city-level plans. We review the implementation of climate action plans through detailed case studies of three large Indian cities—Ahmedabad, Chennai, and Mumbai, using a combination of content analysis of the plans, review of annual municipal climate budgets and in-depth interviews with 12 key practitioners in these cities. As frontrunners of urban climate planning and implementation, these three Indian megacities have made progress on implementation. This is evidenced in terms of institutional setup as well as identification and implementation of sectoral projects aligned with their immediate priorities. All three cities have dedicated at least a third of their annual municipal budget towards climate actions. However, there is limited evidence of whether intended objectives such as emissions reductions, adaptation benefits or other co-benefits were achieved. Implementation challenges include inadequate data availability and governance and low technical capacity within the city governments resulting in heavy reliance on external consultants. The study demonstrates an urgent need to align climate plans with local land-use plans, build in monitoring and evaluation mechanisms, improve accountability and build technical capacity of local government officials at all levels. Without these, it would be difficult to gauge if these plans are on track to meet their stated objectives.</p>