The neonatal presentation of congenital adrenal hyperplasia is either virilization of females or salt loss in both sexes. Early diagnosis is based on the rapid measurement of plasma 17 alpha-hydroxyprogesterone. Milder forms of congenital adrenal hyperplasia can present later in life with abnormalities of somatic or sexual development. The majority of cases of congenital adrenal hyperplasia are clinically diagnosable in the first 2-3 weeks of life: the need for screening for the remaining missed cases and the late onset types remains to be established.