Steroid 21- hydroxylase deficiency accounts for more than 90% of the cases of Congenital Adrenal Hyperplasia (CAH). The classical form of CAH presents in childhood with markedly raised 17- hydroxypregesterone (17-OHP). Neonates are screened for CAH by testing 17-OHP levels to reduce mortality and other serious sequelae. False positive results can occur due to physiological stress. Steroid profiling by LCMS/MS improves the positive predictive value of newborn screening for Congenital Adrenal Hyperplasia (CAH).