Cities are home to 525 million poor people throughout the world. This study assesses the performance of 99 World Bank urban development operations completed since 1993, focusing on how these interventions have improved the living conditions of the urban poor. Findings include that the projects improved livability conditions significantly, including access to better basic water, sewerage and solid waste disposal. However, there is a need for more systematic monitoring and evaluation of the poverty alleviation results of such urban development assistance.