The use, constitution and identification of commercially available button batteries are described. Most cases of button battery ingestion in children are asymptomatic and without complications. Possible complications are reviewed. Most cases described are due to burns in the esophagus or leakage of contents. The danger of intoxication is presumably only present in the case of mercury cells and, even here, it is minimal. If passage of esophagus (for the bigger types pylorus) can is confirmed by x-ray, treatment is conservative observation. If the button battery is present in the esophagus, acute surgical/endoscopic removal are indicated. Possibilities for prevention is described.