The present review is devoted to effects on the newborn of maternal ingestion of caffeine during gestation and lactation. In rodents, caffeine is able to induce malformations, but usually at high doses never encountered in humans; indeed, when caffeine is administered in fractioned quantities during the day, as it is the case with human caffeine intake, caffeine is no longer a teratogen in rodents. Caffeine ingested during gestation induces a dose-dependent decrease in body weight, but only for large doses (> 7 cups/day of coffee), whereas it has no effect at moderate doses. Maternal caffeine consumption during gestation affects hematologic parameters in both rat and human infants and induces long-term effects on sleep, locomotion, learning abilities, emotivity and anxiety in rodent offspring, whereas in humans, more studies are needed to determine the consequences of early caffeine exposure on behavior. Investigators do not agree on the quantities of the methylxanthine found in breast milk, but caffeine does not change breast milk composition, and rather, stimulates milk production. We conclude in this review that maternal caffeine consumption in moderate amounts during gestation and lactation has no measurable consequences on the fetus and newborn infant. Pregnant mothers, however, should be advised to consume coffee and caffeinated beverages in moderation, especially because of the prolonged half-life of caffeine both during the last trimester of pregnancy and in the newborn infant.