Twenty-two girls affected by sexual precocity with impaired final height prognosis were followed until they achieved final height. Twelve of them were treated with an intranasal (D-Ser6)-gonadotrophin-releasing hormone (GnRH) analogue (buserelin) administered at a mean dose of 25 micrograms/kg/day (range 20-32) for a mean period of 14 months (range 8-18). Ten girls refused treatment. Mean final height of the treated girls was 157.3 +/- 8.2 cm, significantly (p = 0.03) higher than the 149.7 +/- 5.5 cm of untreated patients. Treated girls surpassed midparental height (+1.7 cm) while untreated girls reached the lower part of target zone (-3.5 cm). Our data suggest that intranasal buserelin treatment preserves final height in girls with sexual precocity and initially impaired height prognosis.