Urban resilience has become a popular notion among urban policymakers and scientists, as a way to deal with the many complex issues that cities face. While it has positive connotations and resonates with local urban agendas, it is not always clear what it means and what factors contribute to resilience. Additionally, critical literature observes that people’s views on what resilience means can differ strongly and the many choices that are made in planning and implementing resilience are often left implicit. In this paper, we describe a diagnostic tool that tackles these issues by (1) distilling resilience principles and narratives that provide a comprehensive picture of the different pathways that resilience-building could take, and (2) making explicit and facilitating reflection on the choices embedded in planning for urban resilience. We illustrate the tool with an application on urban flood risk management in Rotterdam. We conclude that the Resilience Diagnostic Tool is useful to reflect on the local goals of resilience-building, to diagnose choices made in urban plans, and to reflect on their consequences. It supports policymakers in making deliberate, transparent and goal-oriented choices on urban resilience.