This research will examine the spatio-temporal distribution of common diseases (Acute Respiratory Infections, fever and diarrhoea) among children under five in Sierra Leone and their spatial patterns before and after the implementation of the Free Health Care Initiative (2010) using Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS). The objective is to identify sub-national hot spots of common diseases among children under five between 2008 and 2019. Understanding the spatio-temporal patterns of child health indicators will help in focusing strategies, resources, and interventions where they are needed most.