The mechanism of embolic stroke in young adults remains unidentified in about 35% of cases. In recent years defects in the atrial septum have been described as an important route for cerebral and retinal embolism. These include classical atrial septal defect and patent foramen ovale, as well as the less well-recognized entity of atrial septal aneurysm, with or without interatrial communication. The combined incidence of these defects in the general population is between 20-35%. The introduction of transesophageal echocardiography and the use of echogenic contrast have lead to significant improvement in identification. We describe 3 patients in whom atrial defects were identified as possible routes for cerebral embolism: The first presented with recurrent stroke and combined atrial septal aneurysm and patent foramen ovale. In the second, patent foramen ovale was found in a patient with 2 prosthetic values. The third was a soldier in whom patent foramen ovale was found following transient loss of consciousness. Based on our modest experience and review of the literature we believe that transesophageal and contrast echocardiography should be performed in every young patient with unexplained cerebral ischemia.