The Carbon Monoxide Neuropsychological Screening Battery (CONSB) was developed to improve the neurological assessment of CO-poisoned patients in an emergency setting. Traditional assessment methods (clinical examination and carboxyhemoglobin [CoHb] levels) readily can identify unconscious, severely involved patients; however, many CO-intoxicated patients with cerebral impairment who also require aggressive hyperbaric oxygen therapy are assessed inadequately by such methods. Administration of the CONSB to 66 CO-poisoned patients and 66 volunteer controls revealed significant differences in performance between the two groups. It was concluded that the CONSB enhanced the accuracy of the evaluation of cerebrally impaired CO-poisoned patients. Failure to assess the cerebral functioning of patients exposed to CO and to identify those who require aggressive oxygen therapy could have neurological sequelae.