Neurofibromatosis Type 1 (NF1) is a hereditary neurocutaneous tumour disorder that owes many of its most common features to abnormalities in neural crest-derived cells. NF1 may cause dysplasia in various tissues, even in some tissues that are non-neural crest-derived (eg: bone). While common manifestations of NF1 include café-au-lait spots and neurofibromas, vasculopathies are less common yet noteworthy complications of NF1. NF1 vasculopathies can involve vessels supplying various organs. Cerebrovascular abnormalities associated with NF1 have been sporadically described in the literature; these conditions are of interest due to the incomplete understanding of their pathogenesis and genetics. This book discusses the diagnosis, managements and clinical outcomes for neurofibromatosis.