Objectives : The aim of this study was to assess the effectiveness of acupuncture in treating prehypertension and stage 1 hypertension in postmenopausal women. Methods : The study was a multi-center, four-arm, non-blinded, randomized clinical trial. Sixty participants were randomly assigned to experimental or control groups. The experimental groups received 10 acupuncture sessions over 4 weeks(Group A, n=20) or 20 sessions over 8 weeks(Group B, n=20) along with usual care. The acupoints were GB20, LI11, ST36, and SP6, bilaterally. The acupuncture groups were followed-up for an additional 12 weeks after acupuncture treatment. The control groups received usual care for 16 weeks(Group C, n=10) or 20 weeks(Group D, n=10). The outcomes were blood pressure, blood pressure control rates, lipid profile, and high-sensitivity C-reactive protein(hs-CRP). Results : After 4 weeks, DBP in the acupuncture groups(A+B) showed no significant decrease compared to the control group(C+D). However, after 8 weeks of acupuncture treatment, group B showed a significant decrease in DBP after acupuncture treatment and follow-up period compared to control group. Although there was no difference between the acupuncture and control groups in SBP after acupuncture treatment, group B showed a significant decrease in SBP compared to control group after follow-up period. Lipid profiles and hs-CRP did not differ significantly between acupuncture and control groups. Conclusions : Acupuncture treatment for 8 weeks showed the effect on prehypertension and mild hypertension. To verify the effect of acupuncture on blood pressure, rigorous trials including more participants are required.