Neurofibromatosis type I (NF-I) is an autosomal dominant disorder affecting one in 3000 individuals. Vascular abnormalities are a well-recognized manifestation of NF-I. The purpose of this study is to review the spectrum, management, and clinical outcome of patients with vascular abnormalities and NF-I. We retrospectively reviewed 31 patients (15 males, 16 females) with clinical NF-I and vascular abnormalities identified from imaging or operative findings between 1976 and 2005. The diagnosis of NF-I was made at a mean age of 11 +/- 10 years with vascular lesions identified at a mean age of 38 +/- 16 years. There were 76 vascular abnormalities, including 38 aneurysms, 20 arterial stenoses, 5 arteriovenous malformations (AVM), 5 arteries compressed or invaded by neural tumors, and 6 abnormalities of the heart valves. Arterial lesions were located in the aorta (n = 17) and in the renal (n = 12), mesenteric (n = 12), carotid-vertebral (n = 10), intracerebral (n = 4), and subclavian-axillary and iliofemoral arteries (3 each). Interventions were required in 23 patients (74%); 15 underwent 24 arterial reconstructions, including 9 renal, 8 aortic, 4 mesenteric, 2 carotid, and 1 femoral. The other eight patients had excision of AVM in three, vessel ligation in two, and clipping of cerebral aneurysms, coil embolization of hepatic aneurysms, and left thoracotomy in one patient each. One patient died of ruptured abdominal aortic aneurysm. Six patients (26%) had postoperative complications, including pneumonia in two, and stroke, acalculous cholecystitis, brachial plexopathy and chylothorax in one patient each. The median follow up was 4.1 years (range, 6 months to 20 years). Late vascular problems developed in three patients, including graft stenoses in two and rupture of another aortic aneurysm in one. Freedom from graft-related complications was 83% at 10 years. Patient survival at 10 years was 77%, less than the 86% expected survival for the general population (P < .001). Patients with NF-I have a wide spectrum of vascular abnormalities, most notably aneurysms or stenoses of the aortic, renal, and mesenteric circulation. Operative treatment of symptomatic patients with vascular lesions or large aneurysms is safe, effective, and durable.