The objective of this study was to define the echocardiographic indices predictive of persistence of left ventricular dilatation one year after valve replacement for chronic aortic incompetence. Thirty four consecutive patients (32 men and 2 women, age: 35.6 +/- 10 years) operated for post-rheumatic chronic aortic incompetence, were included in this series. All patients were investigated by echocardiography less than 15 days before and one, six and twelve months after surgery. The parameters studied consisted of measurement of ventricular diameter, shortening fraction and ejection fraction as well as aortic incompetence Doppler indices (jet-left ventriculr outflow tract diameter, jet-left ventricular outflow tract diameter/subaortic diameter ratio, half-pressure time, aortic isthmus end-diastolic velocity). Preoperative echocardiographic data and the results one year after valve replacement were compared for each patient. The left ventricle remained more dilated at one year in patients with a preoperative end-diastolic diameter > 80 mm, an end-systolic diameter > 55 mm, a shortening fraction < 25%, an ejection fraction < 50%, a jet diameter > 16 mm, a jet diameter/subaortic diameter ratio > 65% or a half-pressure time < 350 ms. In conclusion; an end-diastolic diameter > 80 mm, an end-systolic diameter > 55 mm, a shortening fraction < 25%, a jet diameter > 16 mm, a jet diaméter/subaortic diameter ratio > 65% and a half-pressure time < 350 ms appear to represent the main predictive factors of the persistence of ventricular dilatation one year after aortic valve replacement for chronic aortic incompetence.