Twenty patients with left ventricular aneurysms were studied by left ventricular angiography and computed tomography. Measurements of left ventricular short axis, percentage of non-aneurysmal myocardium, and size of aneurysm were determined by both techniques. Qualitative assessments of left ventricular size together with the anatomical relation of the aneurysm to the ventricle were also made. The aneurysm was assessed for resectability by both techniques using these criteria. In all cases there was a distinct and diagnostic change in the contour of the ventricle on computed tomography. Computed tomography indicated eight aneurysms to be unresectable, and this agreed with the angiographic assessment. Of the remaining 12 aneurysms, seven were considered to be resectable on angiography. Computed tomography appears to be a reliable non-invasive technique for identifying left ventricular aneurysms and a useful screening method for identifying unresectable aneurysms.