Patent foramen ovale (PFO) is common, with a probe-patent PFO present in 15-35% of the general population. Patent foramen ovale has been implicated in the aetiology of a number of different pathologies, including cryptogenic stroke, decompression sickness in divers, platypnea orthodeoxia, and migraine with aura. Cardiac ultrasound has a major role not only in the diagnosis of PFO but also in monitoring subsequent therapeutic intervention and in the post-procedural assessment of patients following percutaneous closure. The aim of this review was to outline the data regarding the role of echocardiography in diagnosis, during monitoring and post-procedural assessment so as to provide practical advice to minimize error and optimize patient outcomes. The review will seek to outline the limitations of the available techniques and factors that should be taken into account during percutaneous device closure.