The auxological data of 25 patients (21 girls, 4 boys) with central precocious puberty (CPP), treated for 4 years with a slow-release gonadotropin-releasing hormone agonist [Decapeptyl-controlled release (D-CR) 3.75] every 4 weeks intramuscularly, and of 6 patients (3 girls, 3 boys), treated for 5 years, are presented. After 3 years of D-CR a stabilization of height velocity (HV) at about 4 cm/year was observed. Bone maturation (ratio of change in bone age to change in chronological age; ΔBA/ΔCA) slowed down to a mean ΔBA/ΔCA ratio of 0.5 ± 0.2 (mean ± SD) measured over 48 months. As a result, predicted adult height (PAH) improved from 156.3 ± 7.4 to 162.2 ± 6.8 cm in girls (p < 0.001) and from 174.4 ± 18.6 to 184.3 ± 17.1 cm in boys after 4 years. In the 5th year an ongoing improvement of PAH was observed. 20 additional girls discontinued D-CR for at least 12 months after treatment with D-CR for 2 years or more. In 11 girls menses started after 10.6 ± 3.1 months; 9 girls had no menarche after 12–16 months. HV increased in the first and second 6 months to a level of about 6.0 cm/year, decreased in the third 6 months after cessation to the level before discontinuing D-CR and decreased further afterwards. Bone maturation (ΔBA/ΔCA) increased progressively in the first 18 months after discontinuation, with a stabilization at about 1.3. PAH did not change in the first 12 months after discontinuation of D-CR, but showed a decrease afterwards. We conclude that D-CR treatment is very effective in the long-term suppression of gonadal activity of children with CPP resulting in a stabilization of HV and bone maturation. After treatment the resumption of gonadal activity results in progression of puberty. Preliminary auxological data suggest that the remaining growth potential may be reduced.