Peripheral vascular manifestations of neurofibromatosis are rare but may result in fatal haemorrhaging when they rupture. Surgeons should be aware of this life-threatening condition. We report a case of 35-year-old woman with neurofibromatosis who presented with a swollen and tender mass around her right arm. Angiography revealed 2 aneurysms in the brachial artery. Surgical occlusion revealed a large amount of clotted blood within the subfascial space, and the bleeding point was identified as a pinpoint opening in the aneurysm. The brachial artery abutting the aneurysm and the surrounding soft tissues was extremely brittle and fragile, with massive oozing during dissection. The brachial artery was irreparable and was resected after ligation of the artery and surrounding soft tissues and the aneurysm. Despite an uneventful recovery, the patient died on day 4.