Sixty-three patients with isolated global anoxic-ischemic injury were prospectively evaluated after cardiopulmonary arrest (CPA); 25 (40%) survived, 16 to an excellent recovery, 8 to a good recovery, and 1 with severe deficits. Forty-six percent of the patients achieved full alertness, and only patients who did so survived. Seventy-five percent of patients arousable or initially alert (level of consciousness [LOC] ≥ 4) survived, all but two with excellent outcomes. Twenty-eight percent of patients initially in deep coma (LOC ≤ 3) survived, all with excellent or good outcomes. Ninety percent of patients who became fully alert did so within 72 hours. The likelihood of alerting is correlated with the LOC at given intervals after CPA. Reliable predictions of survival and outcome can often be based upon LOC alone within 2 days after CPA.