The postpartum period, also known as the puerperium, begins immediately after delivery of the neonate and placenta and ends 6-8 weeks after delivery. The appearance of physiologic uterine changes during puerperium can overlap with that of postpartum complications, which makes imaging interpretation and diagnosis difficult. Obstetric and nonobstetric postpartum complications are a considerable source of morbidity and mortality in women of reproductive age, and the radiologist plays an important role in the assessment of these entities, which often require a multimodality imaging approach. US and contrast material-enhanced CT are the techniques of choice in the emergency department, and they can show characteristic radiologic findings that enable differentiation between normal and abnormal features to help radiologists and emergency department practitioners to reach a correct diagnosis and provide timely treatment. The spectrum of postpartum complications ranges from relatively self-limiting to life-threatening conditions that can be divided into six categories: infectious conditions (endometritis), thrombotic complications (eg, deep vein thrombosis, ovarian vein thrombophlebitis, HELLP [hemolysis, elevated liver enzymes, and low platelet count] syndrome, or cerebral sinus thrombosis), hemorrhagic conditions (eg, uterine atony, trauma of the lower portion of the genital tract, retained products of conception, uterine artery arteriovenous malformations, or uterine artery pseudoaneurysm), cesarean delivery-related complications (eg, bladder flap hematoma, subfascial hematoma, rectus sheath hematoma, abscess formation, uterine dehiscence, uterine rupture, vesicovaginal fistula, or abdominal wall endometriosis), iatrogenic conditions (eg, uterine perforation), and nonobstetric complications (eg, acute cholecystitis, acute appendicitis, uterine fibroid degeneration, renal cortical necrosis, pyelonephritis, posterior reversible encephalopathy syndrome, or pituitary gland apoplexy). RSNA, 2020.