Introduction: This study aimed to investigate whether mononucleotide polymorphisms of the angiotensinogen gene at promoter were associated with the blood-pressure-lowering response to telmisartan treatment. Materials and methods: After a two-week single-blind placebo run-in period, 148 patients with mild-to-moderate primary hypertension received monotherapy with 80 mg/day of telmisartan and then were followed up for eight weeks. The -6A/G and -20A/C polymorphisms of the angiotensinogen gene at promoter were determined through polymerase chain reaction and restriction fragment length polymorphsim analysis. The relationship between these polymorphisms and changes in blood pressure was observed and evaluated after eight weeks of treatment. Results: There were no significant differences between -6A/G, -20A/C polymorphisms of the angiotensinogen gene and blood pressure reductions after treatment, p>0.05. Conclusion: It is suggested that angiotensinogen-6 A/G and angiotensinogen-20 A/C polymorphisms were not associated with the antihypertensive response to telmisartan treatment in Chinese patients with hypertension.