With a view to the determination of the effect of the size and localization of cardiac aneurysm upon left-ventricular function and the indications for surgical treatment--35 patients with aneurysms of anterior and posterior walls were complexly examined--hemodynamically, angiocardiographically and coronarographically. A method was applied for the determination of the area of anterior aneurysms. The hemodynamics and cardiac functions were established to be pathologically changed in cardiac aneurysm with an area over 25% of the ventricular surface, with a quickly growing risk for surgical treatment with a surface over 60%. The gravest changes were established in case of anterior aneurysms. The possibilities of faults are discussed as well as of the limited significance of the generally accepted parameters of left ventricular function--end diastolic pressure, end diastolic volume, expulsion fraction and the mean velocity of circumferential contraction along the equatorial plane--in the patients with cardiac aneurysm. The high significance of the changes in the local kinetics is confirmed (percentage contraction of the three main axes and their six semi-axes), both for the residual myocardium and aneurysm. Critical values for the parameters applied are proposed, when the surgical treatment is contraindicated or is with a high risk.