Leuprolide acetate (D-Leu6 des-Gly-NH2(10), Pro-ethylamide9), a synthetic non-apeptide analog of naturally occurring gonadotropin releasing hormone, was used to treat 62 children with central precocious puberty. Sex steroid levels (testosterone in boys and estradiol in girls) were suppressed during treatment lasting from 3.5 to 24.9 months. Basal follicle-stimulating hormone values and both luteinizing hormone and follicle-stimulating hormone peak responses to stimulation by luteinizing hormone releasing hormone were also suppressed, although basal luteinizing hormone values did not differ. Linear growth rate and the rate of bone age advancement decreased during leuprolide therapy. Side effects were minimal. The long-term safety of this treatment has not yet been established; however, leuprolide appears to be an effective long-term therapy for central precocious puberty.