While urban communities -- particularly low-income communities -- have often been involved in specific projects to address climate change, there are ongoing challenges to taking more community-based approaches and mainstreaming them in the broader process of urban governance. Yet at the same time, previous collective action in urban areas demonstrates the potential for contact between individuals and groups, sharing of information, and the development of collective capacity to mobilise in order to benefit more fully from the diversity of opportunities presented within the city. The contributors to this session therefore address two inter-related themes. Firstly, how can urban communities organise and mobilise to negotiate priorities and pursue adaptation strategies that address a broad range of the challenges they face around issues of risk and adaptive capacity? Secondly, how have local governments and other powerful actors incorporated the adaptation experiences, priorities and capacities of these low-income groups in ways that bring community-based adaptation into the urban mainstream? Taken together, the contributions to this session cover experiences of urban community-based adaptation from Africa, Asia and Latin America. They involve perspectives both from local governments and civil society, and highlight both successes and challenges in mainstreaming community-based adaptation in cities.