The differentiation of vasovagal syncope and epileptic seizure is sometimes problematic, since vasovagal syncope may mimic epileptic seizures in many ways. The present report describes a patient who had been diagnosed and treated as having epilepsy with medically-refractory sei-zures for 16 years. Often, unlike epileptic seizures, tonic-clonic convulsions and postictal confusion are uncommon features of vasovagal syncope, but these may occur. Our patient was subjected to subcutaneous injection of one ml normal saline, which caused asystole leading to hypoxia and consequently a typical tonic-clonic convulsion. This patient was proved to have vasovagal syncope. The findings in the present case suggest that the possibility of vasovagal syncope should always be taken into consideration when evaluating patients with medically-refractory or unusual pattern of seizures. In such a circumstance, simultaneous video-electroencephalogram/electocardiogram monitoring may help achieve the correct diagnosis.