The world is urbanizing rapidly. Demographic shifts are intersecting with the impacts of climate change, conflict and displacement. In many parts of the world, chronic stresses mean that large proportions of the urban population are already vulnerable. Rapid and poorly planned urbanization is not just an issue for governments and development specialists; humanitarian actors must also increase their understanding of and ability to operate within towns and cities at risk of crises. Their current approaches do not always adequately reflect and work with the reality of urban populations and the systems that support urban life. This means that humanitarian interventions may not contribute to sustainable urban development and the wellbeing of town and city dwellers in the longer term. This article argues that greater collaboration between humanitarian responders, municipal actors, development specialists and professional associations could lead to better outcomes for crisisaffected populations in both the short and long term.