Abstract This report details the case of a full-term infant, who developed Necrotizing Enterocolitis (NEC) during the first 24 hours of life. While most cases of NEC occur among patients already admitted to the NICU for a variety of conditions, this case develops in a previously healthy newborn who developed early-onset disease. Our analysis describes the factors predisposing to this condition and discusses the most effective antimicrobial treatment strategies. The focus of the article is to highlight the role of certain risk factors (alterations in the gut microbiome, hypertonic formula feeds, perinatal hypoxia and patent ductus arteriosus with left-to-right shunt) in tipping the scale towards the development of NEC.