Among 302 neonates passively addicted to narcotics, 18 had seizures that were attributed to withdrawal. Of those 18 infants, 10 were among the 127 infants exposed to methadone (7.8%), whereas only one of them was among the 83 infants exposed to heroin (1.2%). Generalized motor seizures and myoclonic jerks were the predominant convulsive manifestations. Paregoric was more effective than was diazepam in controlling and preventing these seizures once they occurred. Electroencephalograms were obtained on 13 neonates in the interictal period; 12 of these ECGs were normal. Three infants, two with myoclonic jerks, had paroxysmal brain wave activity at the time of the seizures.