A cryptogenic stroke is one that has eluded an explanation despite complete investigation aimed at uncovering a cause. Since 2003, six randomised trials have collected a large amount of data showing the benefit of patent foramen ovale (PFO) closure compared with standard medical therapy in young patients (aged 18–60 years) with cryptogenic stroke. However, new questions have now emerged concerning the best treatment for people older than 60 years. Traditionally, PFO-related stroke has been considered a disease of younger people, and excluded from the differential diagnosis in elderly patients.