Abstract: AIM:To investigate the effect of dualchamber pacing in the prevention of vasovagal syncope. METHODS: Forty patients with vasovagal syncope who were confirmed by positive headup tilt table testing (HUTT) and had recent recurrent vasovagal syncope were randomly divided into pacemaker group (n=18) and pharmacotherapy group (n=22). All patients were orally administered metoprolol tablets (475 mg, qd). The patients in the pacemaker group were implanted with dualchamber closedloop stimulation (CLS) pacing, whereas patients in the pharmacotherapy group received no other treatment. Patients in both groups were examined again with HUTT 3 months after treatment and were followed up. RESULTS: The positive to negative rate of HUTT was 94% in the pacemaker group and 29% in the pharmacotherapy group, with statistically significant differences between groups (P<0001). During the followup (mean 13±5 months, range: 6-21 months), no patients in the pacemaker group had syncope, although two patients still had significantly alleviated syncope precursory symptoms and signs. Nine patients in the pharmacotherapy group had recurrent syncope, but with fewer attacks. A statistically significant difference was observed in the occurrence of syncope between groups (P<001). CONCLUSION: Dualchamber CLS pacing can prevent the occurrence of syncope in patients with vasovagal syncope.