Pregnancy and the postpartum state can affect preexisting primary neurological conditions, such as headaches and epilepsy. These disorders and their treatment can also have an effect on maternal and fetal pregnancy outcomes. Both seizures and headaches can occur de novo during pregnancy, and if this is the case, they warrant thorough investigation to exclude secondary causes such as vascular, neoplastic, structural, infectious, or other. Migraine headaches can have hormonal triggers and thus may worsen or improve during pregnancy. Seizures during pregnancy can have adverse effects on the mother or fetus, and the benefit of treatment with antiepileptic drugs (AEDs), while potentially teratogenic, is thought to outweigh the risks of the drugs. Levels of AEDs, at least one per trimester, are useful and can guide therapeutic changes in dosing, given physiologic factors that can precipitate alterations of concentration during pregnancy. Pregnant women, or women contemplating pregnancy, should be counseled about folic acid supplementation and postpartum seizure safety issues.