We have evaluated the effect of oral administration of arginine chlorhydrate on the growth hormone response to growth hormone releasing hormone in a group of nine short prepubertal children (six boys and four girls). Arginine chlorhydrate 10 g, administered orally 60 min before an iv bolus injection of growth hormone releasing hormone 1–29, 1 μg/kg, significantly enhanced the growth hormone response to the neuropeptidc, confirming the results of previous studies which used the iv route. Furthermore, our data strengthen the view that the effects of arginine chlorhydrate on growth hormone secretion are mediated by inhibition of endogenous somatostatin relea