Patent foramen ovale (PFO) is a remnant of normal fetal anatomy which may persist into adulthood, mostly asymptomatic. In some adults, PFO may result in a potential for shunting venous thromboembolism to the arterial circulation; less frequently it can cause interatrial, right-to-left shunting of deoxygenated blood. The pathogenesis of several medical conditions is related to the presence of PFO. Some randomized clinical trials have shown evidence of benefit for device closure as compared with medical therapy in patients with cryptogenic stroke. The literature reported several cases of carbon dioxide embolism during general laparoscopic surgery and sometimes stroke after laparoscopic or neurosurgery but there are neither prospective studies addressing these issues, nor randomized clinical trials assessing the effectiveness of pharmacotherapy or interventional procedures at decreasing risk. The European position paper suggests routine monitoring in non-cardiac surgery of patients with a PFO and no actual indications for closure. This article aims to further stratify the risk of periprocedural stroke and paradoxical embolism in this category of patients.