With more than a half of the urban population living in informal settlements and slums (around 56%2) and an urban growth rate of 4.34%3 , the capacity and commitment of Kenya’s 2010 Constitution to address the country’s affordable housing and slum challenge is brought into focus. This impact story explores the frameworks and platforms that Kenya has in place to undertake city-wide slum upgrading and how UN-Habitat’s Participatory Slum Upgrading Programme (PSUP) has helped Kenya’s progress towards a citywide upgrading and prevention approach. Kenya has more than thirty years of slum upgrading experience. It joined the PSUP programme in 2010 and is currently in the implementation phase having mainstreamed the principles and approach very rapidly reflected in, for example, the current draft National Slum Upgrading and Prevention Policy and the draft Urban Development Policy. In light of the country’s ongoing focus on slums and their prevention, Kenya provides an insightful case study and ‘impact story’ on how a city-wide approach could be embraced.