Lead poisoning is a common disease that, if not detected, can lead to developmental delay and other serious sequelae. We report the case of a child with retained intracranial lead pellets from a gunshot injury, in whom elevated blood lead levels were detected approximately 1 year after the injury. No environmental source of lead was found, and a twin sister living in the same dwelling had considerably lower lead levels. The patient's lead levels diminished after each of four courses of chelation, but rebounded each time to potentially toxic levels after termination of therapy. Physicians should be particularly alert in screening for elevated lead levels in children with retained bullet fragments. In patients in whom removal of the bullet fragments is impractical, the potential risks of long-term chelation therapy must be weighed against the risks of lead toxicity.