Congenital adrenal hyperplasia refers to a group of rare genetic disorders affecting the adrenal glands. 21-hydroxylase deficiency is the most prevalent and the most studied cause while the remaining enzymatic defects are less common, accounting for less than 10% of cases. We herein described the clinical, biological and molecular characteristics and outcome of patients of the same family diagnosed with 11-Beta-hydroxylase deficiency. The disorder was revealed by peripheral precocious puberty between the age of 2-3 years in males and by the virilization of the external genitalia in females. Genetics finding a homozygous p.Gly379Val mutation in the CYP11B1 gene. All patients received hydrocortisone supplementation therapy and mineralocorticoid-receptor antagonist. The females underwent a surgical correction of the ambiguous genitalia at the neonatal age. Long term follow-up revealed metabolic syndrome, obesity and hypertension in the first two patients, an impaired final height in the two females and hypokalemia in three patients.