Health outcomes in urban areas are generally better than those in rural areas, but when outcomes in urban areas are disaggregated, large disparities exist between the richest and poorest. Current immunization delivery platforms are based on more stable, sparsely populated, less diverse, and socially coherent communities. However, with rapidly growing urban populations especially in developing regions, immunization programmes need to adapt programme policies and strategies to meet needs of mobile, high density, more diverse urban populations particularly those in slum environments. To facilitate differential urban context immunization programming and complement existing immunization strategies, the Urban Working Group developed an urban immunization toolkit built around six pillars—advocacy and coordination, data for action, context specific service delivery, community engagement, partnerships, and monitoring systems—aimed at addressing the uniqueness of urban areas. The toolkit provides a menu of tailored strategies to deliver life-saving vaccines in urban areas especially to urban poor populations. We encourage country programmes to use this toolkit and provide feedback on best practices, challenges and suggested improvements for subsequent iterations of the toolkit.