Carbon monoxide (CO) is a worldwide environmental toxin and a leading cause of deliberate or accidental poisoning. There is an extensive literature devoted to the clinical features and treatment of those victims who have survived acute CO poisoning for a short length of time. The long-term sequelae of non-fatal poisoning have received scanty references, and the prospects for the long-lasting survivors of acute CO intoxication are less clear. Literature review uncovered reports of only three patients who were followed for a considerable period of time. We present a case of CO poisoning with progressive neurological and psychological deterioration that began 17 years after recovery from a severe, accidental CO asphyxia. The patient was examined in the neurology out patient clinic 29 years after the initial CO intoxication. We believe the unique status of this patient, her similarity to one other case in the literature and the circumstances allowing correlation of the clinical picture to the CO poisoning warrants emphasis.