The optimal management of patients with cryptogenic ischemic stroke found to have a patent foramen ovale (PFO) at diagnostic workup remains unclear. The aims of this observational multicenter study were to evaluate: (1) the risk of recurrent cerebrovascular events in patients with cryptogenic minor ischemic stroke or transient ischemic attack (TIA) and PFO who either underwent percutaneous PFO closure or received only medical treatment, and (2) the risk factors associated with recurrent events. Consecutive patients (aged 55 years or less) with first-ever cryptogenic minor ischemic stroke or TIA and PFO were recruited in 13 Italian hospitals between January 2006 and September 2007 and followed up for 2 years. 238 patients were included in the study (mean age 42.2 ± 10.0 years; 118 males); 117 patients (49.2%) received only antithrombotic therapy while 121 patients underwent percutaneous PFO closure (50.8%). Stroke as the qualifying event was more common in the medical treatment group (p = 0.01). The presence of atrial septal aneurysm and evidence of 20 bubbles or more on transcranial Doppler were more common in the PFO closure group (p = 0.002 and 0.02). Eight patients (6.6%) experienced a nonfatal complication during PFO closure. At the 2-year follow-up, 17 recurrent events (TIA or stroke; 3.6% per year) were observed; 7 of these events (2.9% per year) occurred in the percutaneous PFO closure group and 10 events (4.2% per year) in the medical treatment group. The rate of recurrent stroke was 0.4% per year in patients who underwent percutaneous closure (1 event) and 3.4% per year in patients who received medical treatment (8 events). On multivariate analysis, percutaneous closure was not protective in preventing recurrent TIA or stroke (OR = 0.1, 95% CI = 0.02-1.5, p = 0.1), while it was barely protective in preventing recurrent stroke (OR = 0.1, 95% CI = 0.0-1.0, p = 0.053). The results of this observational, nonrandomized study suggest that PFO closure might be superior to medical therapy for the prevention of recurrent stroke. Periprocedural complications were the trade-off for this clinical benefit. Controlled randomized clinical trials comparing percutaneous closure with medical management are required. Copyright © 2010 S. Karger AG, Basel.