ABSTRACT Background: To investigate the clinical characteristics and treatment of patients who presented with cryptogenic stroke due to pulmonary arteriovenous malformation (PAVM). Cryptogenic stroke is occasionally caused by paradoxical embolization due to a PAVM. Endovascular closure of the PAVM is the preferred treatment, as suggested by isolated case reports. Methods: The authors retrospectively reviewed the charts of 14 patients who underwent endovascular treatment of PAVMs after an ischemic cryptogenic stroke. The patients were treated by a single interventionalist over a 15-year time period at Columbia University Medical Center. Results: All patients had suffered a prior cryptogenic stroke and 50% (7/14) experienced more than one stroke. Nearly all patients (13/14) had been referred for closure of a patent foramen ovale (PFO) diagnosed by transthoracic echocardiogram (TTE). During catheterization, use of intracardiac echocardiography, probing of the septum and local injection of saline revealed that only 29% of patients (4/14) actually had a PFO. A total of 18 PAVMs were identified: 56% were isolated right-sided, 22% were isolated left-sided, and 22% were bilateral. The majority (16/18) were simple type PAVMs with a single feeding vessel. Gianturco coils were used to treat eight patients and Amplatzer devices were used to treat seven patients (two patients received both coils and Amplatzer). No patient suffered recurrent stroke after shunt closure. Conclusions: Endovascular closure of PAVMs after cryptogenic stroke appears safe and may reduce recurrent stroke risk in this select population. Frequently, PAVM is misdiagnosed as PFO by noninvasive TTE and incidentally discovered at catheterization to close the PFO.