Button batteries are easily swallowed by children and may produce severe digestive injuries through two different mechanisms: electrochemical burns when in contact with the digestive mucosa, release of caustic substances when fragmented. Esophageal lesions are especially dangerous, as they can lead to perforation, fistula or secondary stenosis. The risk of mercury intoxication is less worrying since the assimilated fraction of the metal is unlikely to produce clinical effect. Although the large majority of the reported cases of button battery ingestion remained asymptomatic, the potentially lethal outcome justifies a precise diagnostic procedure: any button battery ingestion must be documented with a radiography of the digestive tract. Any battery lodged in the esophagus must be urgently removed by endoscopy. Other locations do not need any removal attempt unless complications: nonetheless a follow-up is necessary to confirm the spontaneous elimination of the battery. Manufacturers, physicians and parents share responsibility for preventing such accidents.