Cogenital adrenal hyperplasia (CAH) is a family of genetic disorders from a deleterious mutation in a gene encoding adrenal steroidogenic enzyme essential for cortisol biosynthesis. Recent molecular advances have provided the genetic basis for the phenotypic variability in CAH, a means for accurately genotyping family members of CAH patients including prenatal prediction of the genotype in fetuses at risk of the disorder, and have helped to better define the hormonal criteria for the varying spectrum of CAH disorders. Biochemical advances have simultaneously aided the diagnosis and therapeutic monitoring of CAH patients. Prenatal maternal dexamethasone therapy for fetal CAH prevents or minimizes virilizing sequelae in the majority of prenatally treated affected females, but was associated with significant maternal side effects. Newborn screening for CAH has contributed to the prevention of morbidity of delayed diagnosis of CAH in more than two third of affected neonates. Current treatment methods, however, may not be optimal for achieving normal genetic height and appropriate weight in CAH patients, and more effective approaches to CAH therapy remain to be explored.