Systemic hypertension is usually considered idiopathic, though it might be associated to an increase in the sympathetic nervous activity due to other metabolic disorders, such as hyperinsulinemia/insulin resistance. Thus, hypertensive and normotensive subjects were investigated in this study, and their plasma insulin levels were determined after 12h fasting by Microparticle Enzyme Immunoassay. Homeostatic Model Assessment of Insulin Resistance (HOMA IR) values were accessed by the equation: insulin (mU/ml) x glucose (mmol/l) / 22.5. Furthermore, the insulin resistance was also evaluated by the ratio triglyceride/HDL-cholesterol. Enzymatic tests were processed in the blood sample of 183 individuals, and blood pressure was measured according to the "V Comitê Nacional sobre Hipertensão – Brazil". 31% of the subjects were hypertensive, and showed significantly higher values of insulin (mean ± standard error of the mean of 14.1±1.4), values of HOMA IR (4.3±0.6) and of the triglyceride/HDL-cholesterol ratio (4.2±0.4), when compared to insulin levels (9.9±0.8), HOMA IR (2.3±0.2) and triglyceride/HDL-cholesterol ratio (3.0±0.3) in the normotensive individuals (ANOVA: p=0.0097, p=0.0002 and p=0.0069, respectively). It was also observed that systolic and diastolic pressure values increased as a positive function of these three variants (Z Test, p<0.05). Therefore, this work suggests that hyperisulinemia/insulin resistance has an important role in the idiopathic systemic hypertension. Thus, this clinical detection may improve and give a better individual prognosis. Supported by CNPq