This study is conducted mainly to analyse the effect of water and sanitation on childhood mortality in Sub-Saharan Africa region. The empirical approach uses longitudinal data sourced from the World Development Indicators for the period 2000-2015. Infant and under-five mortality rates were used as indicators for childhood mortality. To diminish the possible confounding influence of water and sanitation in the child mortality regressions, we use an instrumental variable approach based on Dynamic Panel estimators or the General Method of Moment. The study finds that in Sub-Saharan Africa region, water and sanitation has a strong impact on reducing both infant and under-five mortality rates. Furthermore, the study finds that public health expenditure and aid all work together to reduce the possibility of infant and under-five deaths in Sub-Saharan Africa countries. These findings call for policymakers to pay a great deal of attention to increase investment in water and sanitation, improving official development assistance(ODA) along with increased public spending on health as these are all important factors that can help to decrease infant and under-five deaths in Sub-Saharan Africa.