Fluoxymesterone was found to be comparable to methyltestosterone in accelerating growth of physically normal pre-adolescents in a short-term controlled study. Both androgenic agents accelerated bone age more than height age, although there was considerable variation within the study groups. Similar findings were observed in a group of normal children of short stature, who were given varying regimens of fluoxymesterone therapeutically, but in this series an occasional subject realized greater growth than advancement of epiphysial maturation. Under the conditions of this study fluoxymesterone has no clear advantage over other orally given androgens as a growth stimulant. It should be used with the same good judgment and reservation required of all androgens, lest the ultimate stature of some children be compromised. The many factors that may operate in determining the response to such agents are poorly defined at present.