The polymorphisms of ACE gene is investigated using polymerase chain reaction for detection of ACE I/D genotype frequency in hypertensive cases in sector of Egyptian population. Serum ACE is significant higher in hypertensive group than normotensive one (27.5± 4.4 and 21.3± 5.4 ng mL-1, respectively. Mean SBP (systolic blood pressure), DBP (diastolic blood pressure) and urinary protein excretion in DD genotype were 181±17 mmHg, 112±19 mmHg, 3.8±0.48 mg mL-1 and 141.5± 36.8 mg day-1, respectively but in II genotype these were 142± 10 mmHg, 99± 13 mmHg, 4.35±0.4 mg mL-1 and 116.4± 36 mg day-1, respectively. In hypertensive patients, serum ACE levels in DD, ID and II genotypes were 36.2± 5.7, 22.1± 3.7 and 24.5± 4.9 unit ?, respectively. D/D ACE gene polymorphism plays a role in the development of target organ damage in severe essential hypertension and might have a prognostic value. It can be considered as one of the risk factor of hypertension.