The question as to whether treatment with short-acting or with slow-release gonadotropin-releasing hormone (GnRH) agonists has different effects on growth and bone maturation when treating girls with central precocious puberty has not yet been studied. In a meta-analysis, we compared 21 naive girls with central precocious puberty who were treated with buserelin with 22 naive girls with central precocious puberty who received Decapeptyl in depot form. Treatment lasted for at least 18 months. At the start of therapy, chronological age, bone age, growth velocity and pubertal stage in the two groups were very similar. During the first 6 months of treatment, significantly more phases of incomplete suppression of pituitary-gonadal activity occurred in the buserelin group. As a result, growth velocity and bone maturation (Δ bone age/Δ chronological age) remained significantly higher than in the Decapeptyl Depot group (p < 0.0001 and p < 0.01, respectively). In contrast to the Decapeptyl Depot group, the height standard deviation score (SDS) for bone age in the buserelin group did not change significantly in the first 6 months of treatment, and the predicted adult height decreased. Between the 6th and 18th months of therapy, the development of growth rate, Δ bone age/Δ chronological age, height SDS for bone age and predicted adult height in both groups became almost identical. However, the rate of growth and bone maturation in the buserelin group remained faster than in the Decapeptyl group, though not significantly so. The mean predicted adult height had risen significantly after 18 months in the Decapeptyl Depot group but not in the group treated with buserelin. Treatment with the slow-release GnRH agonist Decapeptyl Depot is more effective for children with central precocious puberty than therapy with the short-acting agonist buserelin, not only with regard to long-term compliance but also for auxological reasons, since Decapeptyl Depot suppresses gonadotropins and oestradiol faster and more completely at least during the first 6 months of treatment.