This case explores a study which aimed to tackle the drivers of young child malnutrition by strengthening municipal governance. Such governance is inherently political because it involves deciding how to allocate limited resources across the city. To achieve this aim, the researchers intervened using Participatory Action Research (PAR) with a multi-sectoral group of professionals from the health and health-related sectors in the cities of Mombasa, Kenya and Valparaiso, Kenya. This case study focuses on the research in Keya. The researchers used the PAR process to build capacity for multisectoral planning and action and to influence change in policy and practice. The impact of this intervention on child nutritional status was measured using a controlled design. In this case study, the three-phase research design is elaborated together with some of the practical decisions that had to be made at each step of the research process from proposal writing to completion. Some of the successes are reported and then the challenges faced are analyzed with a discussion of how they were overcome. Finally, key practical lessons learned from the experiences gained in the study are identified. It is hoped that these lessons may be of use to other researchers wishing to use these methods to influence policy and practice in different contexts.