The final adult height in patients with growth deficiency treated with growth hormone has been shown to depend upon pubertal development. This is mainly related to the shortening of puberty duration and accelerated bone maturation. A long acting analogue of gonadoliberin, Trp-6-GnRH, has been given to 17 patients with isolated growth hormone deficiency in order to delay pubertal progression. In seven of these patients, GH treatment and the analogue of Gn-RH were initiated simultaneously. The other 10 patients had been treated for more than one year with hGH at the onset of the analogue. Mean duration of treatment was 17 months. Annual growth rate was low in all cases. Statural progression was parallel to the delayed bone maturation without change in the ratio of statural maturation to bone maturation. No significant change in height prediction was observed after the combined treatment. Combination of the long-acting analogue of gonadoliberin, Trp-6-Gn-RH, with growth hormone in GH-deficient patients does not seem to be an appropriate way to improve final height after the onset of spontaneous puberty.