This chapter describes various imaging modalities and safety concerns associated with a person when used during pregnancy or in the immediate postpartum period. The radiation effects to the fetus are categorized into deterministic and stochastic effects. Plain radiography and fluoroscopy, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine scan are the most commonly used imaging modalities during pregnancy. Following intravenous administration, very low level of iodinated or gadolinium-based contrast agents is excreted in breast milk and ingested by the infant. The advantages of the nuclear medicine scan are lower radiation dose to the maternal breast and the avoidance of intravenous iodinated contrast. Trauma is a major cause of maternal and fetal mortality, and imaging choices in this setting should be prioritized for fast and accurate diagnosis. CT evaluation is strongly recommended in patients with an acute abdomen who suffered abdominal trauma.