: Transesophageal echocardiography is frequently performed for further evaluation of sources of embolism and better evaluation of atrial septum in patients with cerebral ishemic events. Although two-dimensional transesophageal echocardiography can depict atrial septal aneurysm and patent foramen ovale, the full extent of the patent foramen ovale cannot be easily discerned in some cases. We describe a patient with transient cerebral ischemia where three-dimensional echocardiography provided incremental value when compared to two-dimensional transesophageal echocardiography in the assessment of atrial septal aneurysm and patent foramen ovale.