Neurofibromatosis type I (NFI), also called Von Recklinghausen disease, is an autosomal dominant disease secondary to a genetic mutation on the long arm of chromosome 17. This disorder affects neural crest cells. Cutaneous clinical forms are the most frequent with multiple benign skin neurofibromas, associated with café au lait skin spots and iris hamartomas. Vascular abnormalities in NF1 are rare but have also been well described. The most frequent abnormalities are characterized by arterial aneurysm degeneration, stenosis, and malformations. Venous locations are rare, but some cases of venous aneurysms were described with ruptures as complications. We present a rare case of thrombosed venous femoral aneurysm associated with a pulmonary embolism in a patient affected by NF1.