Growing attention to the urban politics of policy failure focuses on the ways in which policymaking is politicized before, during, and after moments of failure, and the effects of policy failure in urban political process. We argue three trends are apparent: (1) Policy failure is arelational process rather than an end state, emerging from long term interactions between political actors and governance institutions. (2) In urban politics the definitions of “failure” and “success” can be fluid, and rhetorically weaponized for political gain. (3) Policy failures can have generative effects after apolicy fails, for instance, by catalyzing funding or establishing institutional path dependencies. This collection contributes to urban geography by establishing avocabulary and set of analytical techniques for researching spatial aspects of policy failure. The authors in this special issue build an empirical and theoretical baseline for future research, illustrating diverse mechanisms and outcomes of urban policy failure.