Twenty-five children (23 girls and 2 boys) with central precocious puberty were treated with the LH-RH agonist D-Ser (TBU)6-LHRH (1-9) EA (HOE 766, Buserelin) by daily subcutaneous injection for a period of 11-18 months. Eight girls and 2 boys previously treated with cyproterone acetate (CPA, 100-150 mg/m2 body surface per day) and the first seven newly diagnosed patients received 2 X 10 micrograms Buserelin/kg bodyweight per day for 1 week, followed by a maintenance therapy of 1 X 10 micrograms/kg per day. After an initial marked increase, oestrogen (E2) serum levels in girls and testosterone (T) values in boys decreased. After a treatment period of 6-20 weeks the patients received 2 X 20 micrograms Buserelin/kg per day for 1 week and thereafter a maintenance dosage of 20 micrograms/kg per day to obtain full suppression (i.e. E2 less than 50 pmol/l; T less than 1 nmol/l). The remaining eight patients started directly on 2 X 20 micrograms Buserelin/kg per day followed by 1 X 20 micrograms/kg per day. All eight girls with menarche before therapy had no further menses. In all girls there was a reduction of palpable breast tissue. Decrease of pubic hair development was observed in 3 girls, an increase was seen in 5 girls, whereas in the remaining 15 girls no change was observed. Both boys had a reduction of testicular volume and of pubic hair.(ABSTRACT TRUNCATED AT 250 WORDS)