Pregnant women present to the emergency department (ED) for both pregnancy and nonpregnancy-related complaints and often require imaging studies as part of their diagnostic evaluation. Imaging studies can include ultrasonography, radiography (x-rays), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine studies. Radiographs, CT, and nuclear medicine studies confer radiation, while ultrasound and MRI do not. Ultrasound and MRI are not associated with risk and are the imaging modalities of choice for the pregnant patient. The radiation exposure of almost all radiography, CT, and nuclear medicine studies is well below the dose threshold associated with fetal harm and should not be withheld from the pregnant patient if indicated. A challenge for emergency physicians is how to use medical diagnostic imaging appropriately and safely without placing the mother and the fetus at unnecessary risk. These decisions depend on the clinical scenario, and the risks that are posed to mother and fetus depend on the gestational age of the pregnancy. To make better and more informed decisions, emergency physicians must understand the benefits, risks, and radiation exposure of different imaging modalities and be able to engage the pregnant patient in shared decision-making.