Objective:To evaluate the relationship between ACE-gene polymorphism and left ventricular geometry in never treated hypertensives. Methods: We enrolled 200 hypertensive outpatients that underwent clinical and ambulatory blood pressure measurements, echocardiographic evaluation and analysis for insertion (I)/deletion (D) polymorphism by PCR. Patients with normal or increased (>125 g/m² in males and >110 g/m² in females) left ventricular mass were considered to have concentric remodeling or concentric left ventricular hypertrophy if their relative wall thickness was ≥0.45. Results: The left ventricular mass index values (g/m²) were 136±30 in DD genotype, 124±26 in ID genotype, and 116±20 in II genotype (DD vs. ID P<0.005; DD vs. II P<0.05), and were unrelated to blood pressure. Ninety-six patients presented left ventricular hypertrophy (48.0%): 51 with concentric and 45 with eccentric hypertrophy. The eccentric left ventricular hypertrophy was detected in 32 (36.8%) DD patients, in ten (10.5%) ID patients (P<0.05), and in three (16.6%) II patients. The relative septal thickness was 0.43±0.09 in DD genotype, 0.45±0.08 in ID genotype, and 0.43±0.10 in II genotype. In DD and ID genotypes, the relative posterior wall thickness (0.37±0.07 vs. 0.41±0.07; P<0.0001) and the end-diastolic left ventricular internal dimension (52.8±3.3 mm vs. 48.3±2.8 mm; P<0.0001) were statistically different. Conclusions: The DD genotype of the ACE-gene is associated with an increased left ventricular mass and with a significantly higher prevalence of eccentric left ventricular hypertrophy, when compared to ID genotype.