Abstract The patent foramen ovale (PFO), a relatively common and generally benign finding, has been associated with paradoxical embolisms. The closure of PFO, performed in patients with cryptogenic stroke, has been shown to reduce the recurrence rates of ischemic events, as evidenced by recent clinical trials. In this article, the authors synthesize the crucial role played by echocardiography in this context, from diagnosis and risk stratification to planning and monitoring of percutaneous intervention.