Acute chorioamnionitis occurs relatively frequently in pregnancy and may result in significant fetal and neonatal morbidity. Although there is no unanimity of opinion regarding the most efficacious antibiotic regimen for the treatment of this complication, there is a consensus, at least among obstetricians, that maternal treatment may have an impact on neonatal outcome. It appears that the fetus and neonate benefit from "intrauterine" treatment. Virtually all antibiotics cross the placenta, and fortunately most are relatively safe for use during pregnancy.