Echocardiographic examination of the left ventricle was performed in a group of 50 patients with various heart diseases. Five methods proposed for left ventricular pump function calculation were used, based on measurements of ventricular end-diastolic diameters. The results have shown that all tested methods of determining the ejection fraction or its functional equivalent (fractional shortening) correlate significantly with the ejection fraction obtained from the considered angiocardiographic technique. The closest correlation (r=0.771) was found when the ejection fraction was calculated from volume values determined by the cubed formula. Among other methods, that of fractional shortening and ejection fraction derived from those values seemed to be well interpretable. Other methods of ejection fraction calculation have a rationale in some cases, but have also their specific limitations.