We have treated eight cases of childhood ingestion of alkaline disk batteries, one resulting in an esophagotracheal fistula. These batteries are capable of rapid tissue destruction on contact with moist membranes. We recommend that packaging include proper warning of this hazard and urge that retained batteries be promptly removed from the esophagus and stomach by endoscopy or laparotomy. If the battery has reached the small intestine, further transit should be monitored carefully by roentgenographic studies until recovery. Perforation is possible after eight-hour retention at a specific site.