In this study 41 preterm neonates from NICU were screened for hypothyrodism versus 46 normal fullterm neonates. There was significant differences among the free thyroxine being decreased as reported by other authors. However the thyrotropin (TSH) was significantly increased versus the control group. 5 preterm neonates showed to have transient hypothyroidism 4 of which regained normal as proved by second step estimation. Thus follow up must be done by serial estimation ofTSH and FT4 until the neonate reaches normal hormonal thyroid level.