Foramen ovale plays a key role in foetal circulation, however it may remain patent after birth throughout the life. Its patency is so frequent in healthy people (27-35 %), such as to be considered a variant of normal. It is at risk of complications, like paradoxical embolism by right to left shunt with stroke, migraine, temporary blindness, as well as aneurysm, thrombosis and endocarditis of the fossa ovalis. There is no doubt that it should be considered a congenital heart disease at all effects. Invasive cardiology closure with umbrella and even with stiches is nowadays feasible and indicated in specific clinical scenarios. Further research is needed to determine whether cardiac echo-doppler screening for identifing affected patients as a primary prevention measure is advisable.