Started in 2016 at Queen Elizabeth Central Hospital (QECH), Malawi, CHAIN Study is a prospective clinical study that aims at improving our understanding of which children are at highest risk of death from acute illness and in the post-hospital discharge, and identifying modifiable risk factors that may be targeted by interventions to effectively identify and manage these children. The study targets 500 acutely ill children in Malawi aged 1 month to 2 years across a spectrum of nutritional status at admission to hospital and follows them up through discharge from hospital, then for a further six months. In addition, the study also targets 125 children in the community who are not acutely ill in order to establish community norms for demographic and biological factors. Malawi in one among many countries participating in The Childhood Acute Illness & Nutrition (CHAIN) Study Network. Other participating countries include Kenya, Uganda, Bangladesh and Pakistan.