BACKGROUND Uterine arteriovenous malformation (AVM) is a rare but potentially life-threatening medical condition. It is a congenital or acquired structural abnormality that may result in potentially life-threatening bleeding. Due to the nonspecific symptoms, this condition may be mistaken for more benign causes of vaginal bleeding, thus potentially leading to adverse outcomes and delay in diagnosis and treatment. Most cases of uterine AVM are acquired, and the post-partum period is an especially vulnerable time. CASE REPORT This is a case of a 26-year-old woman who presented to the Emergency Department with post-partum vaginal bleeding. During her evaluation, a uterine AVM was suspected based on Doppler ultrasound and was confirmed with computed tomography angiography. The patient was admitted to the hospital and treated with catheter embolization with complete resolution of bleeding and return to normal activities shortly after discharge. CONCLUSIONS This report describes a hemodynamically stable patient who presented to the Emergency Department with post-partum vaginal bleeding caused by a large uterine AVM. Despite her benign initial presentation clinically, she had a potentially life-threatening condition that could have resulted in significant morbidity if the diagnosis had been missed or delayed. It is important to maintain a high index of suspicion for even benign-appearing vaginal bleeding in the Emergency Department and to obtain the appropriate diagnostic studies to rule out potentially dangerous causes, especially in the setting of recent pregnancy or gynecologic instrumentation.