City governments are well-positioned to effectively address urban health challenges in the context of rapid urbanization in Asia. They require good quality and timely evidence to inform their planning decisions. In this article, we report our analyses of degree of data-informed urban health planning from three Asian cities: Dhaka, Hanoi and Pokhara. Our theoretical framework stems from conceptualizations of evidence-informed policymaking, health planning and policy analysis, and includes: (1) key actors, (2) approaches to developing and implementing urban health plans, (3) characteristics of the data itself. We collected qualitative data between August 2017 and October 2018 using: in-depth interviews with key actors, document review and observations of planning events. Framework approach guided the data analysis. Health is one of competing priorities with multiple plans being produced within each city, using combinations of top-down, bottom-up and fragmented planning approaches. Mostly data from government information systems are used, which were perceived as good quality though often omits the urban poor and migrants. Key common influences on data use include constrained resources and limitations of current planning approaches, alongside data duplication and limited co-ordination within Dhaka's pluralistic system, limited opportunities for data use in Hanoi and inadequate and incomplete data in Pokhara. City governments have the potential to act as a hub for multi-sectoral planning. Our results highlight the tensions this brings, with health receiving less attention than other sector priorities. A key emerging issue is that data on the most marginalized urban poor and migrants are largely unavailable. Feasible improvements to evidence-informed urban health planning include increasing availability and quality of data particularly on the urban poor, aligning different planning processes, introducing clearer mechanisms for data use, working within the current systemic opportunities and enhancing participation of local communities in urban health planning.