In victims of carbon monoxide (CO) poisoning, metabolic acidosis has been considered a clinical finding of ominous prognostic importance. In previous studies, such patients either died or suffered serious neurologic sequelae, resulting in the recommendation by some authors that these patients require more complicated therapy, including hyperbaric oxygen and hypothermia. This report documents the full neurologic recovery of three patients with severe metabolic acidosis and CO poisoning. Our experience indicates that acidosis may not be as important a prognostic factor as previously thought, and that randomized prospective trials are needed in such patients before more complicated therapy becomes accepted medical practice.