OBJECTIVE: To observe the short-term and long-term clinical effect on posterior circulation ischemic vertigo treated with "xiao xingnao kaiqiao" acupuncture (minor regaining consciousness and opening orifice) and explore its effect mechanism. METHODS: Ninety patients with posterior circulation ischemic vertigo were randomly divided into a treatment group and a control group, 45 cases in each group. The patients of the two groups were all treated on the base of neurological medicine. In the control group, Flunarizine Hydrochloride was prescribed for oral administration (5 mg, once daily, for 21 days totally). In the treatment group, acupuncture of "xiao xingnao kaiqiao" was provided at Yintang (EX-HN3), bilateral Neiguan (PC6), bilateral Sanyinjiao (SP6), Baihui (GV20), bilateral Fengchi (GB20), bilateral Wangu (GB12) and bilateral Tianzhu (BL10). The needles were retained for 30 min, once daily for 21 days totally. The changes in vertigo score of traditional Chinese medicine (TCM) were observed, and the changes in the mean blood velocity (Vm) of the left vertebral artery (LVA), the right vertebral artery (RVA) and the basilar artery (BA) as well as the vascular pulsatility index (PI) were monitored and determined by transcranial Doppler (TCD). Additionally, the recurrence rate was followed up after 3 months to evaluate the long-term clinical effects. RESULTS: After treatment, the total effective rate of the treatment group was 91.11% (41/45) and 75.56% (34/45) in the control group. The total effective rate in the treatment group was higher than that in the control group (P<0.05). Compared with their own pre-treatment, the vertigo scores of TCM were reduced in either the treatment group or the control group after treatment (P<0.05) and the score in the treatment group was lower than that in the control group (P<0.05). Compared with their own pre-treatment, Vm and PI were all improved after treatment in either group (P < 0.05). After treatment, the improvements in Vm and PI of LVA、RVA and BA in the treatment group were better than those in the control group (P<0.05). In the follow-up after 3 months, the recurrence rate was 19.51% (8/41) in the treatment group and was 50.00% (17/34) in the control group. The recurrence rate in the treatment group was lower than that in the control group (P<0.05). CONCLUSION: "Xiao xingnao kaiqiao" acupuncture obviously relieves the clinical symptoms of posterior circulation ischemic vertigo. The mechanism of acupuncture is potentially related with its effects in improving Vm and PI of LVA,RVA and BA, as well as improving blood supply of brain tissue.