Ecthyma gangrenosum (EG) is a cutaneous manifestation of invasive infection usually caused by pseudomonas, but can be caused by many bacteria, fungal and viral infections. We present the first reported case of EG caused by invasive Escherichia coli in a neonate. A neonate presented with evidence of sepsis and a rapidly evolving 3×3.5 cm(2) well-circumscribed haemorrhagic and necrotic ulcer on the left groin. There was evidence of decreased perfusion of the lower limb owing to pressure effect of the ulcer. The child responded well to anticoagulation and antibiotic therapy. It is crucial to clinically suspect EG and promptly start empiric antibiotic therapy covering pseudomonas to decrease the morbidity and mortality. However, other viruses, fungus and bacteria including E coli should also be considered in the differential diagnosis of EG in a neonate.