A variety of acute breast complaints may present to the emergency department, and it is important for radiologists to be familiar with the important clinical and imaging findings of these pathologies. Although mammography is more commonly utilized for breast imaging, ultrasound is a first-line choice of assessment for acute breast complaints in the emergency department, as it is more readily available and better tolerated by patients. This chapter will review the clinical background and imaging findings of a variety of breast pathologies, which may be seen in the emergency setting, as well as to provide a brief review of management and potential complications. It will cover infectious, inflammatory, traumatic, iatrogenic, pregnancy- or lactation-related, and augmentation-related breast emergencies.