The calcification of ligamentum arteriosum occurs after the normal closure of the ductus arteriosus. Foreign body ingestion is a common event in the pediatric age, and it is frequently addressed in the Emergency Room. We report a case of foreign body in a patient with unknown calcification of the ligamentum arteriosum. His parents noted blood in the saliva, but he had no symptoms indicative of an acute clinical situation. The CT showed a hyperdense object in the aorto-pulmonary window with features compatible with a metallic object. The child underwent surgery, during which a calcified ligamentum arteriosum was found and no foreign body. This phenomenon has been described to be better identified using multi-section CT scans than X-Rays.