21-Hydroxylase deficiency (21-OHD) is the most common cause of congenital adrenal hyperplasia, with an incidence of 1:14000 live births and equal prevalence among males and females. Newborns with the most severe "salt-wasting" form of 21-OHD are susceptible to salt-wasting crises in the first few weeks of life. This is associated with morbidity and mortality. 21-OHD newborn screening (NBS) is currently performed in many countries. Despite several prominent medical societies recommending 21-OHD NBS, no state in Australia currently screens for this condition. We report a case that illustrates the need to reconsider including 21-OHD in NBS. 21-OHD NBS can be reliable, sensitive and effective in reducing morbidity and mortality.