Objectives: To assess the efficacy of gonadotropin suppression and compare the treatment outcome of 1- and 3-month depot formulations of gonadotropin releasing hormone (GnRH) agonist in girls with central precocious puberty (CPP). Methods: A total of 76 girls with CPP treated with a GnRH agonist were retrospectively reviewed. Of them, 15 received triptorelin pamoate 11.25mg 3-month depot (A group), 30 received triptorelin acetate 3.75mg 1-month depot (B group), and 31 received leuprolide acetate 3.75mg 1-month depot (C group). Luteinizing hormone (LH) and follicle-stimulating hormone and estradiol levels were measured at 30 minutes after GnRH agonist injection at months 3, 6, 12. Chronological age (CA), bone age (BA), height standard deviation score (SDS), and predicted adult height ( PAH) of patients were also examined at baseline, months 6 and 12. Results: Baseline clinical characteristics did not differ in three groups. Mean LH concentrations obtained at 30 minutes after GnRH agonist injection at months 3 were 0.66 ± 0.23 IU/L in A group, 0.53 ± 0.25 IU/L in B group, and 1.34 ± 0.78 IU/L in C group. The proportion of patients with suppressed LH response (3 IU/L) was 93.3 % (14/15) in the A group, 100 % (30/30) in B group, and 87.1 % (27/31) in C group from months 3 to 12. At 6 and 12 months, the height SDS for BA and PAH were increased compared with baseline in all three groups. Increase in height SDS for BA during 12 months were 0.10 ± 0.47, 0.12 ± 0.30, 0.07 ± 0.26 in A group, B group, and C group, respectively ( P=0.835). Increase in PAH during 12 months were 2.46 ± 1.02 cm, 1.71 ± 2.36 cm, 1.63 ± 1.87 cm in A group, B group, and C group, respectively ( P=0.452). The BA advancement decreased during treatment and were not significantly different in all three groups at months 6 and 12 ( P=0.692 and P=0.103, respectively). Conclusion: Regardless of the 1-month or 3-month formulations, all GnRH agonists showed similarly effective suppression of gonadotropin and treatment outcome of growth in CPP girls.