Between 1954 and 1973, 101 heroin-addicted mothers gave birth to 149 babies at Vancouver General Hospital. Thirty-seven percent of the infants had low birth weights and two thirds were born preterm. Average birth weight was 2,710 gm as compared with an overall average of 3,420 gm for this hospital. Tobacco and alcohol abuse, and poor maternal nutrition probably contributed to the growth retardation. Withdrawal symptoms were observed in 68% of the babies, and this may have been aggravated by multiple drug use, which was prevalent, including alcohol, barbiturates, and "soft drugs." Neonatal mortality rate of 6.7% and a stillbirth rate of 4% resulted in a perinatal mortality rate of 10.7%. Prematurity, respiratory distress syndrome, and other perinatal complications related to an unfavorable social background accounted for most neonatal deaths, but none was attributable directly to narcotic withdrawal.