In infants delivered by cesarian section, the immune system could be influenced by anesthetic drugs that may cross the placenta and reach the fetal circulation. Factors that determine placental transfer of anesthetics and their distribution into and ultimate removal from fetal tissue include physiochemical properties of the compound; the anatomic features of the maternal circulation, placenta, and fetus; and the hemodynamic and pharmacokinetic events that occur within them. Because the anesthetic agents can interfere with many neonatal function, the aim of this manuscript is to review the interference of regional or general anesthesia on neonatal immune response.