Six girls with the non-salt-losing form of congenital adrenal hyperplasia are described. Diagnosis was delayed in five, the range of ages of diagnosis being 19 months-7 years. In the sixth, despite early diagnosis and medical treatment, surgery was delayed electively until she was 3 years old. The five in whom diagnosis was delayed were all virilized with a markedly advanced bone age and reduced adult height prognosis. Diagnosis was delayed for a variety of reasons: misinterpretation of laboratory data (one), lack of availability of medical assistance (one), language problems (one), maternal inexperience (one), and failure of the doctor to recognize an obvious clinical abnormality (one). All six children came from immigrant families, and all except one was born in a major centre. None was born before 1979.