Transcranial Doppler (TCD) is a very sensitive tool for detecting microembolic signals (MES) in the brain vessels after injection of air-mixed saline in case of right-to-left shunt (RLS). Patent foramen ovale (PFO) can be found in nearly one-half of migraineurs with aura, and, reciprocally, the prevalence of migraine in patients with stroke with PFO is exceedingly high. We aimed to monitor the passage of MES in the brain vessels during transcatheter closure of PFO and to subsequently follow-up patients for both the efficacy of the procedure and the severity of migraine. Seventeen patients suffering from migraine with aura (MA+, n = 8) or without aura (MA-, n = 9) scheduled to undergo transcatheter closure of PFO with Amplatzer PFO occluder devices for paradoxical cerebral embolism were monitored with contrast TCD (DWL, Germany) before, during, and after the procedure to estimate the magnitude of the shunt. Spontaneous embolization to the brain was also recorded. The patients were thereafter followed-up at 1, 3, and 6 months. A composite score of migraine severity, which included frequency, duration, and intensity of the attacks in the previous 3 months (range 0-10), was obtained at the time of the procedure and at the follow-up visits. Complete occlusion of PFO was achieved in all patients after 1 month in most cases. Preoperatively, the migraine score was 6.75 in MA+ and was 6 in MA--patients. After closure, the score dropped to 2.5 in MA+ and to 4.2 in MA--patients at the 6-month follow-up visit, the difference being statistically highly significant in both groups. Overall, 5 of 17 patients no longer complained of migraine, 10 of 17 were substantially improved, and two of 17 were unchanged at 6 months. Migraine aura disappeared in six of eight patients. Closure rate was very satisfactory, from a preoperative average bubble count of 42 to an average of 4 bubbles in the four patients in whom a small residual shunt was still detectable at the 6-month follow-up visit. TCD monitoring provides the most accurate assessment of RLS at the brain level. Closure of PFO with transcatheter devices results in the substantial relief of migraine in patients with stroke with large RLS.