Cardiac arrhythmias are among the most common cardiac complications encountered during pregnancy. In some, pregnancy may trigger exacerbations of pre-existing arrhythmias, whereas in others arrhythmias may manifest for the first time. Fortunately, severe arrhythmias requiring aggressive or invasive therapies are rare. There are unfortunately few randomized studies, little data on the efficacy or safety of antiarrhythmic drugs (AADs), or even explicit guidelines to support decision making on pregnant women with arrhythmias. Thus, much of the clinical care is guided by knowledge of the physiology of pregnancy and educated risk/benefit decisions made in collaboration with high-risk obstetric colleagues in Maternal-Fetal Medicine, as well as with the patient.