Previous studies have suggested that children with neurofibromatosis type 1 are shorter than their unaffected counterparts as an effect of a germline NF1 gene mutation. The pathophysiology of this effect is still uncertain. The purpose of this study was to characterize longitudinal growth in children with neurofibromatosis type 1 in order to assess growth velocity and its influence on stature. Longitudinal height data were collected for 188 patients with a confirmed clinical diagnosis of neurofibromatosis type 1. Children with neurofibromatosis type 1 had population mean heights statistically different from the general population, with a reduced peak height velocity during pubertal growth. In addition, there were no significant differences in the timing of peak height velocity during puberty between the general population and those with neurofibromatosis type 1. These data demonstrate that short stature in neurofibromatosis type 1 is due in part to subnormal height acquisition during puberty.