Closure of patent foramen ovale (PFO) has been proposed as an alternative to anticoagulation in patients with presumed paradoxical emboli. We report the immediate and mid‐term results of the phase 1 U.S. Multicenter Clinical Trial of patients who underwent transcatheter PFO closure for paradoxical embolism using the new Amplatzer PFO device. Fifty patients (28 male/22 female) underwent catheter closure of their PFOs at a mean age of 41 ± 11 years. Thirty‐six patients had ischemic stroke, 10 had transient ischemic attack, and 4 had peripheral embolism. Seventeen patients had atrial septal aneurysm. The implantation procedure was successful in 49/49 patients; one patient did not have a PFO. Complete closure was seen immediately after the procedure in 26/49 patients; 17 had minimal residual shunt, 4 had moderate and 2 had large residual shunts. The median fluoroscopy time was 10.5 min (2.8–43 min). There were no complications related to the device. One patient developed an arteriovenous fistula at the catheter site requiring surgical repair. At a mean follow‐up interval of 16.5 ± 7.2 months, there were no deaths or recurrent neurological or peripheral embolic events. Eight patients reported an episode of dizziness or palpitations (four of them within 18 days of the procedure). No episodes of atrial dysrhythmias were noted. Contrast bubble study at last follow‐up documented complete closure in 45/48 patients; one patient had minimal, one had moderate residual shunt, and one had a large shunt. One patient was lost to follow‐up. We conclude that catheter closure of PFO associated with stroke/transient ischemic attack or peripheral embolism using the new Amplatzer PFO device is a safe and effective method in preventing recurrence of such episodes. Randomized clinical trials comparing device closure versus continued medical therapy are underway. Catheter Cardiovasc Interv 2003;60:524–528. © 2003 Wiley‐Liss, Inc.