SUMMARYLeft ventricular hypertrophy in patients with hypertension is a main clinical prognostic entity. The aim of this study was to evaluate the association between mutations at genes of the renin‐angiotensin system (RAS) and the development of left ventricular hypertrophy. Genetic polymorphism in angiotensinogen (AGT) and angiotensin ll‐type 1 receptor (AT1R) genes was examined in a group of well‐selected essential hypertensive Caucasians with left ventricular involvement (n=40) and a group of healthy unrelated Caucasians (n=150). Cardiac morphology and function were assessed by M‐mode echocardiography. Molecular variants were analysed by amplified fragment length polymorphism. We observed a statistically significant difference both for AGT and AT1R genotype distribution in patients with left ventricular hypertrophy compared with controls (p<0.05). A 0.49 and 0.225 frequency was detected among cases for T and C mutant alleles at AGT and AT1R genes. Mutations in RAS genes are involved in the pathophysiology of target‐organ damage in essential hypertension. Evaluation of molecular factors conferring a risk of developing heart involvement may lead to better identification of patient subgroups and more effective control of the clinical course.