Results from several observational studies indicate an association between migraine and patent foramen ovale (PFO). Several biological mechanisms have been proposed to explain this link, including shared genetic inheritance. However, there is currently insufficient evidence to support a causal link between PFO and migraine. Although the results of uncontrolled observational studies suggest the PFO closure may have a beneficial effect on migraine frequency, a large randomized trial failed to support such a conclusion. Until there is more evidence from ongoing large controlled trials, PFO closure should not be performed in clinical practice for the prophylaxis of migraine.