Near-adult height (AH) was determined in 121 children (72 males and 49 females) with GH deficiency (GHD) who were prepubertal when they began treatment with recombinant DNA-derived preparations of human GH. AH as a SD score was -0.7 +/- 1.2 (mean +/- SD), significantly greater than the pretreatment height SD score (-3.1 +/- 1.2), the predicted AH SD score (-2.2 +/- 1.2; Bayley-Pinneau method), and the height SD score at the start of puberty (-1.9 +/- 1.3). In contrast to studies of GH treatment outcome, which used pituitary-derived GH (pit-GH) in lower doses, we found that males did not have a higher AH SD score than females, spontaneous puberty did not diminish AH, and AH was significantly greater than that predicted at the start of GH treatment. In a multiple regression equation, the statistically significant variables (all P < 0.0001) related to AH (r2 = 0.70) were the following: duration of treatment with GH, sex (males were taller than females, as expected for the normal population), age (younger children had a greater AH) and height at the start of GH, and growth rate during first year of GH. For the AH SD score (r2 = 0.47), pretreatment predicted AH, duration of GH, and bone age delay were significant (P < 0.0002) explanatory variables. Bone age delay (chronological age-bone age) had a negative impact on the AH SD score. Target height, etiology of GHD, previous treatment with pituitary GH, and the presence or absence of spontaneous puberty did not significantly improve the prediction of AH. Early diagnosis of GHD and continuous treatment with larger doses of GH to near AH should improve the outcome in children with short stature due to GHD.