Arteriovenous malformations are an acknowledged cause of migraine that can long constitute the only clinical manifestation before bleeding. We describe two cases of patients suffering from symptoms like migraine with aura in whom arteriovenous malformations were detected by transcranial Doppler examination. We suggest that a screening of migraine patients to prevent bleeding from a possible underlying unruptured arteriovenous malformation could be performed by using transcranial Doppler, a non-invasive and low cost examination.