Introduction: The true incidence of blunt breast trauma is unknown due to a paucity of relevant literature. A retrospective chart review of 5,305 female blunt trauma victims reported an incidence of 2% of female blunt breast trauma (FBBT), which was most often following motor vehicle collisions (94%) and associated with long bone and rib fractures (45% and 44%, respectively). The vast majority of patients had simple hematomas that were managed expectantly. A small subset (6.5%) had expanding hematomas which required surgical evacuation (Saunders et al, 2011). Here, we describe a patient who presented in extremis with multiple injuries including a rapidly expanding breast hematoma necessitating urgent surgical intervention. This case highlights the importance of prompt recognition and treatment of FBBT in the trauma patient. A 51 year old female presented to the trauma resuscitation unit in extremis following a high-speed head-on motor vehicle collision with multiple injuries including grade II splenic laceration, right olecranon and patella fractures, bilateral ankle fractures, several rib fractures, bilateral pneumothoraces, and a rapidly expanding breast hematoma. Upon arrival, the patient was hypotensive and was urgently intubated. Despite the placement of bilateral chest tubes, her hypotension failed to resolve and her hemoglobin dropped from 9.1 to 5.7 g/dL. Clinically, there were signs of expansion of the hematoma in her left breast. Following resuscitation, the patient was taken urgently to the operating room for a left chest wall exploration and hematoma evacuation. A curvilinear incision was made in the upper portion of the left breast and the tissues were dissected down to the subcutaneous layer. A large hematoma was evacuated and the breast tissue was noted to be discolored, likely due to hematoma or direct injury. There was pulsatile hemorrhage from large branches supplying the pectoralis major muscle, which were ligated with 2-0 Vicryl ties. Other wounds were irrigated and packed tightly. The patient was transferred to the intensive care unit post-operatively, and orthopedic surgery managed the care of her multiple fractures. Three days following the initial procedure, the patient was brought back to the operating room for re-exploration of the left chest wall. At that time, there was no evidence of ongoing hemorrhage or any need for debridement. The pectoral muscle was closed with 2-0 Vicryl, a Jackson Pratt drain was placed deep in the wound, and the subcutaneous breast tissue was closed in multiple layers with 2-0 Vicryl. The skin was closed with a running 4-0 Monocryl subcuticular suture. The patient's post-operative course was uncomplicated and she was discharged to acute rehab approximately 2 weeks following admission. FBBT is an understudied entity; however, as the above case illustrates, breast hematomas can be the underlying cause of refractory hypotension and unchecked hemorrhage in the female blunt trauma patient. Concomitant injuries, particularly multiple fractures and pneumothoraces, as well as mechanism of injury, in this case a high speed motor collision, can raise the suspicion of FBBT in the trauma patient with visible signs of breast tissue damage who fails to appropriately respond to resuscitation and traditional interventions. Further research is needed to fully appreciate the incidence of FBBT and to aid in the establishment of guidelines in the management of breast hematomas. Many can be treated conservatively with close observation, but as in the case described, exploration, evacuation of the hematoma, and surgical control of hemorrhage may be required to prevent further decompensation of the patient.