Among 215 patients referred for percutaneous closure of patent foramen ovale (PFO) after presumed paradoxical embolism, we assessed the prevalence of migraine. In the year prior to PFO closure, 48 (22%) patients had migraine, twice the expected prevalence of 10 to 12% in the general European population. In patients with migraine with aura, percutaneous PFO closure reduced the frequency of migraine attacks by 54% (1.2 +/- 0.8 vs 0.6 +/- 0.8 per month; p = 0.001) and in patients with migraine without aura by 62% (1.2 +/- 0.7 vs 0.4 +/- 0.4 per month; p = 0.006). PFO closure did not have an effect on headache frequency in patients with nonmigraine headaches (1.4 +/- 0.9 vs 1.0 +/- 0.9 per month; p = NS).