During the past 5 years there have been 22 newborn infants born of mothers who were narcotic addicts at the Flower and Fifth Avenue Hospitals and the Metropolitan Hospital in New York City. It is the purpose of this paper to present the clinical findings in these infants and notes on treatment. Of the 20 mothers (there were two sets of twins), 18 were taking heroin, one morphine, and in one the drug could not be determined. The maternal dosage of heroin ranged from 2 to 45 mg/day. The route of administration was intravenous in 14, subcutaneous in one, intranasal as snuff in one, and unknown in four. Birth weights ranged from 1,100 to 3,600 gm with a mean of 2,600 gm. Nine weighed less than 2,500 gm and three weighed more than 3,200 gm. All of the infants were normally developed. Twenty newborn infants demonstrated clinical findings with onset from birth to the fourth day. In 16 of these, symptoms and signs were present during the first 24 hours. In all of these 20 infants there were tremors, excessive crying, sleeplessness, restlessness, or hyperirritability. Vomiting and poor feeding were observed in 10 infants, diarrhea in 6, yawning and sneezing in 6, fever in 4, and convulsions in 1. There was apparently a direct relationship between severity of the infant's signs and symptoms and the size of the maternal narcotic dosage. There was complete recovery of all the newborn infants. The diagnosis presented no problem when a clear history of maternal narcotic addiction was available. However, this history was often not elicited or was emphatically denied. Careful physical examination of the mother usually revealed needle marks and other stigmata of narcotic addiction.