Background: Congenital adrenal hyperplasia is one of the most common inherited endocrinal disorders. Steroid 11β hydroxylase deficiency is the 2nd most common form of CAH. It is a rare AR disorder caused by CYP11B1 mutations with an incidence of 100,000–200,000 in overall population. Objectives: To study the percentage of CAH due to 11βHydroxylase deficiency in patients presenting with clinical manifestations and hormonal findings suggestive of Congenital adrenal hyperplasia.Patients and methods: The study was cross sectional, including 20 patients (16 females and 4 males) with CAH, divided into 2 groups (11β hydroxylase deficiency and 21 hydroxylase deficiency) according to 11 deoxycortisol/cortisol ratio. Both groups were studied regarding history (demographic data, family history, age at presentation, different presentations), examination (BP measurement, auxology, genitalia, pubertal staging) and investigations including laboratory tests (adrenal precursors, PRA, Na, K) and imaging (pelvic U/S). Results: Both groups showed no statistically significant difference regarding age at presentation, sex, consanguinity, different clinical presentations, BP assessment, auxology, Prader scoring in females with atypical genitalia, adrenal precursors (except for 11 deoxycortisol level and 11 deoxycortisol/cortisol ratio which were highly significant with a p value of < 0.001), PRA, Na and K levels. Conclusion: Differentiation is very difficult between 21OHD and 11βOHD and in order to properly diagnose 11βOHD, measurement of 11 deoxycortisol is mandatory for all cases with suspected CAH, especially that routine use of mineralocorticoids in 21OHD might be injurious in 11βOHD prone to hypertension. Furthermore, the need for genetic studies is increasing especially for those patients with atypical presentation (salt wasting 11βOHD).