Neonatal sialadenitis of the submandibular gland is a very rare clinical entity. Information about the etiopathogenesis and management of the disease is very limited. Prematurity, prolonged gavage feeding and dehydration are the frequent causes. This report presents a rare case of isolated suppurative submandibular sialadenitis in a full-term newborn without any risk factors. Possible etiology, diagnosis and management of this uncommon disease are discussed.