One hundred and fourteen consecutive patients who underwent aortic valve replacement (AVR) for isolated aortic regurgitation (AR) from 1965 to 1981 are presented. Sixty eight (60%) were preoperatively in NYHA class I-II and 46 (40%) were in NYHA class III-IV. Eighty-two patients had left and right heart catheterization prior to the operation and the severity of regurgitation was assessed angiographically in 93% of those in functional class (FC) I-II. Left ventricular (LV) end-diastolic volume index and end-systolic volume index were elevated even in the mildly symptomatic patients (156.1 and 61.0 ml/m2 respectively). The ratio of LV end-systolic pressure to LV end systolic volume index was diminished in the FC I-II patients. Two patients in FC III died in hospital (operative mortality: 1.7%) and there were 21 late deaths with a 5-year survival of 82.7%. Late survival differed significantly between patients who were preoperatively in FC I and II or III and IV (P less than 0.03). These data suggest that severe AR with altered LV function is an indication for early operation regardless of the presence of absence of symptoms