Subvalvar left ventricular aneurysms are rare and occur predominantly in black Africans. A submitral left ventricular aneurysm was diagnosed on cross sectional echocardiography in a black woman born in the United Kingdom. The left parasternal long axis view showed a highly echogenic mass apparently attached to the wall of a dilated left atrium, but the apical two-chamber view showed that this was thrombus in the apex of a left ventricular aneurysm. The patient subsequently underwent surgical correction.