essential hypertension is considered a multifactorial trait resulting from a combination of environmental and genetic factors. the angiotensin ii type 1 receptor mediates the vasoconstrictor and growthpromoting effects of ang ii. the a1166c polymorphism of the at1 receptor gene may be associated with cardiovascular phenotypes, such as high arterial blood pressure, aortic stiffness, and increased cardiovascular risk. we investigated the association between this a1166c polymorphism and hypertension in hypertense and normotense subjects from san luis (argentina) by mismatch pcr-rflp analysis. hypertense patients exhibited significant increases in lipid related values and body mass index. the frequency of occurrence of the c1166 allele was higher among patients with hypertension (0.19) than in the control group (0.06). no significant association was found between this polymorphism and essential hypertension in the study population, although the ac genotype prevalence was higher in patients with hypertension and positive family history of hypertension (32%) than in control subjects (12%). patients with the a1166c polymorphism exhibited higher levels of serum total cholesterol, ldl-cholesterol and bmi than in control subjects. taken together the genotype and biochemical parameters and considering the restrictive selection criteria used, the present results suggest a correlation between at1 a1166c gene polymorphism and risk of cardiovascular disease.