Routine neurological examination of patients one hour after cardiac arrest seems to be of value in determining the prognosis for life and likelihood of intellectual impairment.In 48 patients 53 episodes of cardiac arrest were followed by serial neurological examinations. Patients were divided into two groups according to neurological findings one hour after cardiac arrest. Patients in group 1 were unresponsive or at most responded in a reflex fashion to painful stimuli at one hour; these patients died or survived with intellectual damage. Patients in group 2 responded purposefully at one hour and survived without neurological damage. These patients commonly showed transient confusional states and a variety of other non-focal abnormalities, and focal signs were seen occasionally.