A 42-year-old was admitted to our institution for recurrent episodic dyspnea on exertion. The patient had also a history of recurrent transient ischemic attacks. Careful history taking revealed that she developed dyspnea in an upright position, whereas the symptoms were relieved in a supine position (platypnea). The patient was given the diagnosis of platypnea-orthodeoxia syndrome. Transthoracic echocardiography showed cardiac situs solitus levocardia with great artery transposition with intact interventricular septum, patent foramen ovale (PFO) and moderate right atrial dilatation. Agitated saline contrast injection demonstrated the presence of spontaneous right-to-left shunt. The patient underwent transcatheter closure of PFO. After percutaneous closure of PFO patient became asymptomatic and hypoxemia induced by orthostatic conditions did not appear again. A transthoracic echocardiography performed after two months, showed the complete closure of PFO, without residual shunt.