The response to growth hormone (GH) therapy was studied in children born small for gestational age (SGA; n = 593) and in those with Silver-Russell syndrome (SRS; n = 127) using data from KIGS (Kabi International Growth Study). For the SGA patients, median birth weight was -2.6 SD scores (SDS), treatment was started at a median age of 9.2 years, at a time when median height was -2.8 SDS while median target height was -1.4 SDS. For the SRS patients, median birth weight was -3.1 SDS, treatment was started at a median age of 7.0 years, at a time when median height was -3.4 SDS with a median target height of -0.1 SDS. GH treatment increased height SDS in both SGA children and patients with SRS; in 16 SGA patients treated to (near) final height with GH (median dose, 0.7 IU/kg/week), height minus target height SDS was -2.0 at the start of treatment and -1.0 at final height. In conclusion, the results obtained in KIGS indicate that GH treatment of short children born SGA is effective in increasing final height above the predicted height and in achieving the target height.