Over a 10-year-period, 78 Saudi children with congenital adrenal hyperplasia were seen at King Khalid University Hospital, Riyadh. Of these, 20 (25.6%) patients from 11 families were 11 beta-hydroxylase deficient. Their mean age was 2.8 years (range 0-10 years). The clinical expression was somewhat severe; pseudoprecocious puberty in males and variable degrees of virilization in females which led to wrong sex assignment in seven (58.3%). Three patients had neonatal salt-wasting before treatment. Moderate to severe hypertension associated with hypokalaemia was present in another six. In four siblings hypertension persisted inspite of adequate hydrocortisone therapy. It is concluded that congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency is relatively frequent among the Saudi Arabian population. In view of the severity of the clinical expression and complications, physicians should be aware of the disease and have a high index of suspicion in order to detect and treat such patients early enough to avoid or minimize the unwanted sequelae.