Introduction: Oxidative stress is involved in many diseases, including hypertension, kidney failure, and heart disease. This study aimed to evaluate the effect of hydroalcoholic Cichorium intybus extract on blood pressure in rats. Antioxidant activity, phenolic and flavonoid contents of the plant extract were also evaluated. Methods: In this study, 32 male Wistar rats weighing 250-300 g were divided into four groups of eight each. Animals in the control group were administered with normal saline and in the C. intybus groups with extract at 25, 50, and 100 mg/kg for two weeks. Then, the homodynamic parameters were examined by the Power lab. The phenolic and flavonoid contents were also evaluated by a spectrophotometer and the rate of free radical scavenging activity was measured by the diphenyl-1-picyryl-hydrazyl (DPPH) free radical method. Results: The free radical scavenging activity of C. intybus extract was obtained 47. 85% of DPPH, and flavonoid and phenolic contents were 8. 21 and 27. 19 mg/g of dry extract, respectively. Meanwhile, median (MAP), systolic (SAP) and diastolic arterial pressure (DAP) significantly decreased in the 50 mg/kg extract-treated group compared to the control and 200 mg/kg extracttreated groups. Conclusion: Ethanol extract of C. intybus plays a protective role against hypertension, which, in part, might be due to antioxidant compounds of the plant against free radicals.