We report the case of a 56-year-old woman who was admitted because of left pulmonary embolism. An episode of ischemic stroke occurred during hospitalization. Transesophageal echocardiography revealed a right atrial appendage thrombus and a patent foramen ovale with right to left shunting. This suggested paradoxical embolism across a patent foramen ovale as the most reasonable explanation of the ischemic stroke in this patient, in the presence of right cardiac overload secondary to the hemodynamically significant pulmonary embolism. The patient's clinical conditions dramatically improved after anticoagulant therapy.