IntroductionRapid urbanisation in Kenya has resulted in growth of slums in urban centres, characterised by poverty, inadequate social services and poor health outcomes. The government's initiatives to improve access to quality healthcare for mothers and children are largely limited to public health facilities, which are few and/or inaccessible in underserved areas such as the slums. The ‘Partnership for Maternal, Newborn and Child Health’ (PAMANECH) project is being implemented in two Nairobi slums, Viwandani and Korogocho, to assess the impact of strengthening public–private partnerships for the delivery of healthcare on the health of mothers, newborns and young children in two informal settlements in Kenya.Methods and analysisThis is a quasi-experimental study; our approach is to support private as well as public health providers and the community to enhance access to and demand for quality healthcare services. Key activities include: infrastructural upgrade of selected Private Not-For-Profit health facilities operating in the two slums, building capacity for healthcare providers as well as the Health Management Teams in Nairobi, facilitating provision of supportive supervision by the local health authorities and forming networks of Community Health Volunteers (CHVs) to create demand for health services. To assess the impact of the intervention, the study is utilising multiple data sources using a combination of qualitative and quantitative methods. A baseline survey was conducted in 2013 and an end-line survey will be conducted at least 1 year after full implementation of the intervention. Systematic monitoring and documentation of the intervention is on-going to strengthen the case for causal inference.Ethics and disseminationEthical approval for the study was obtained from the Kenya Medical Research Institute. Key messages from the results will be packaged and widely disseminated through workshops, conference presentations, reports, factsheets and academic publications to facilitate uptake by policymakers.Protocol registration numberKEMRI- NON-SSC-PROTOCOL No. 393.