After restoration of spontaneous circulation and adequate oxygenation, 262 comatose survivors of cardiac arrest were randomly assigned to receive standard brain-oriented intensive care or the same standard therapy plus a single intravenous loading dose of thiopental (30 mg per kilogram of body weight). The study was designed to have an 80 percent probability of detecting a 20 percent reduction in the incidence of permanent postischemic cerebral dysfunction. Base-line characteristics were similar in the two treatment groups. At the end of one year of follow-up, there was no statistically significant difference between treatment groups in the proportion of patients who died (77 percent of the thiopental vs. 80 percent of the standard-therapy group), survived with "good" cerebral recovery (20 percent of the thiopental vs. 15 percent of the standard-therapy group), or survived with permanent severe neurologic damage (2 percent of the thiopental vs. 5 percent of the standard-therapy group). The results of this study do not support the use of thiopental for brain resuscitation after cardiac arrest.