We determined the frequency of traumatic brain injury (TBI)-related growth hormone deficiency (GHD) from a large registry of growth hormone-deficient subjects and compared these subjects' clinical characteristics with those of children with idiopathic growth hormone deficiency (IGHD). A surprisingly small number of subjects with TBI-induced GHD (n = 141) were registered compared with those with IGHD (n = 23,722). At onset of treatment, the subjects with TBI-induced GHD were older (P = .045), had lower height velocity (P < .001), had a greater number of other pituitary hormone deficiencies (P < .001) and, after a year of recombinant human GH treatment, demonstrated a greater change in height velocity (P = .016). We speculate that TBI-induced GHD may be a neglected phenomenon in childhood, and recommend prospective longitudinal studies to explore its natural history and frequency.