In Africa up to a quarter of children will visit a health facility in their final illness; many dying on the day of admission. Targeted emergency care may be a very cost-effective means of reducing child mortality, but has not been afforded a high enough priority. Moreover, the most basic treatments provided in the emergency room have never been subjected to evaluation in clinical trials, including in resource-rich settings. The controlled FEAST trial of fluids resuscitation demonstrated that guidelines, developed for the rest of the world, cannot be safely translated to Africa. Although oxygen is a basic element of hospital care, there are no relevant trials to guide which level of oxygen saturation or the best method of how to administer it (low flow or high flow) improves outcome. In practice many children in low-income countries do not receive oxygen, despite being recommended, owing to the lack of its availability due to the high cost, or supplies that are unpredictable (erratic delivery of cylinders and/or electricity) Outcomes of children in sub-Saharan Africa with pneumonia, remains poor with an in-hospital mortality 9-10% (for those with oxygen saturations between 80% and 92%) and 26-30% case fatality for those with oxygen saturations <80%. The Children’s Oxygenation Administration Strategies Trial (COAST) will start in 2017 in 3 countries and will enrol 4,200 children (aged 2m to 12y) with presumptive pneumonia and hypoxaemia (defined as SpO2<92%). The key questions COAST will establish are whether liberal oxygenation for SaO2≥80% will decrease mortality compared with a strategy that includes permissive hypoxia (usual care); and whether use of high flow oxygen delivery will decrease mortality (at 48 hours and up to 28 days) compared with low flow oxygen delivery (usual care).