Brachial artery PA can be from 3 etiology:congenital, systemic disease, and trauma. Penetrating injury is most common mechanism.1 Clinical symptoms including redness, induration/ pulsatile mass and pain, Most case of brachial artery PA has delay presentation. In the literature review only 1 case was found for blunt traumatic mechanism not associated without humeral fracture,Inthese two cases were all diagnosed by US. Duplex US has good sensitivity and specificity in postcatheterizationpatients[3] Typical US finding including cystic lesion adjacent to a supplying artery, ying-yang sign in cystic mass, to end fro sign.[4] US also can be used in treatment, like ultrasound guide thrombin injection. Other diagnostic tools including CTA or angiography, but all have radiation.