The effects of drug addiction in perinatal period and its clinical, diagnostic and therapeutic problems have been considered. The authors reported five cases of newborns from addicted mothers. Neurologic symptoms were present in all cases, gastro-intestinal disturbances were present in two newborns. One presented with convulsions and died for severe hyaline membrane disease. One newborn was small for gestational age and one was premature. Treatment has been carried out successfully with diazepam and/or phenobarbital in four cases. The authors stress the importance for a careful methadone program during pregnancy in order to reduce prematurity and neurologic sequelae of the narcotic withdrawal syndrome.