Nineteen (30%) of 63 adult survivors of cardiopulmonary arrest had seizures after admission to the hospital. Eleven of 19 had more than one type of seizure. Myoclonic seizures began within 12 hours of the arrest in eight patients, and after 3 or more days in four patients. Only two (17%) patients with myoclonic seizures survived. Partial seizures usually began within 12 hours of the arrest and0 were controllable with anticonvulsants; 4 of 12 patients survived. Two of four patients with generalized tonic-clonic seizures survived; one of four with “shivering” lived. Overall, patients with seizures had a survival rate of 32% (6 of 19), compared with 43% for patients without seizures. None of the survivors had recurrent seizures within 6 months after hospital admission.