The authors undertook a retrospective study of 41 patients in whom an atrial septal aneurysm (ASA) had been diagnosed at transoesophageal echocardiography performed for ischaemic cerebrovascular events in 26 cases. No significant differences in this size, thickness or mobility of the ASA or the associated cardiac abnormalities were demonstrated in this context. However, patients presenting with cerebrovascular accidents were older, had several cardiovascular risk factors and more cardiac arrhythmias. These arrhythmias were usually related to other cardiac pathology such as ventricular hypertrophy or chronic cor pulmonale. Moreover, the probability of the cerebrovascular accident being related to the ASA was only acknowledged in 11 cases. These results mean a certain degree of discretion in diagnostic investigation and therapeutic management of these cases.