Six neonates are described with a gangrenous omphalitis, a disease not reported for many years. They had many features in common including previous good health. In two, the disease was preceded by the application of tobacco ash to the umbilical stump. Clinically there was gangrene of the umbilicus with a blood-stained discharge and extensive cellulitis radiating into the abdominal wall. Despite aggressive therapy including excision of the affected area, the systemic effects of the local disease progressed rapidly until all of the first five infants who presented, died. Microbiologically there was a polybacterial infection involving a wide variety of organisms particularly E coli and Clostridia species. There appeared to be an appropriate response by the infants to an acute bacterial infection, and two patients investigated showed no evidence of cellular or humoral immunodeficiency. The pathology was an infection causing local tissue necrosis with a vasculitis and microabscess formation, which involved adjacent structures by direct extension. The severe systemic symptoms were attributable to an endotoxemia or exotoxemia. The evolution of therapy for gangreneous omphalitis in the newborn, successful in the sixth patient, is discussed.