The relations of serum growth hormone (GH), free testosterone (T), and free triiodothyronine (T3) concentrations to the head circumference, height, and weight were studied in the human neonates. Blood was taken from the umbilical cord immediately after the birth, to measure the hormone concentrations. GH was found to be inversely correlatd with the bodily measures in the female neonates; there were no significant correlations between these variables in males. In females, free T3 negatively linearly correlated with GH, and positively linearly correlated with the neonatal head circumference, height, and weight. Serum free T levels was found to be positively linearly correlated with GH, and negatively linearly correlated with the neonatal body measures in the same subjects. It was suggested that GK may exert growth reducing effects through T3 and T during perinatal development.