A rare vascular pathology, true brachial artery aneurysms make up just 0.17% of peripheral artery aneurysm cases. Arteriovenous fistulas (AVFs) as well as AVF ligation carry a risk of resulting in the rare late complication of brachial artery aneurysms. Here, we present the case of a 69-year-old man with a history of AVF ligation who developed a brachial artery aneurysm assessed perioperatively with duplex Doppler ultrasound.