The current doses of recombinant growth hormone (rGH) are two to three times those used in the pituitary growth hormone era. These rGH doses (0.025 to 0.043 mg/kg/d) are similar to or moderately greater than the physiologic requirements. Growth velocity and height gains have been shown to be greater with 0.05 mg/kg/d of rGH than with 0.025 mg/kg/d. Larger doses of GH and early initiation of treatment result in greater heights at the onset of puberty and greater adult heights. Earlier onset of puberty and more rapid maturation, as indicated by bone age, were not observed in children who were given 0.18 to 0.3 mg/kg/wk of rGH. The frequency of adverse events is very low, but diligent surveillance of all children who are treated with rGH is essential.