Neurofibromatosis 1 is a progressive disorder that affects multiple systems of the body. Management is currently focused on anticipatory guidance, genetic counseling, and symptomatic treatment of specific lesions, usually through surgery. Insights into pathogenesis of the disorder are beginning to suggest possible mechanisms of treatment, and clinical trials have begun for some types of lesions. The unpredictable natural history and variable phenotype present challenges for clinical trials in neurofibromatosis 1, which will need to be addressed to develop a system for reliable testing of potential therapies.