The appropriate timing of intervention in patients with chronic aortic incompetence allows recovery of ventricular function. We sought to determine the optimal timing of the Ross procedure for chronic aortic incompetence in young patients. We retrospectively analysed case notes, and measured pre- and postoperative echocardiographic indexes of left ventricular function, in patients who had undergone the Ross procedure for chronic aortic incompetence. Methods and results: We found 21 patients with preoperative and postoperative data suitable for analysis. Their age at operation ranged from 5.6 to 26 years, with a median of 13.8 years, and the duration of follow-up was from 0.5 to 6.8 years, with a median of 2.4 years. The preoperative left ventricular end-diastolic dimension was converted to a z-score, and this was used as a threshold to divide the population. Using the threshold of a preoperative left ventricular z-score of more than 3 to divide the population did not show any difference in postoperative parameters of left ventricular function. Significant differences were found postoperatively, however, in both the left ventricular z-score and the ratio of left ventricular end-diastolic radius to posterior wall thickness in diastole, with a cutoff preoperative threshold z-score greater than 4. Conclusion: The increase in the ratio of left ventricular end-diastolic radius to the thickness of the posterior wall in diastole would suggest that there is disruption of left ventricular short axis architecture and myocardial contractile function when intervention is postponed. The significantly larger left ventricular dimension at end-diastole, despite the reduction in volume loading post surgery, may also demonstrate irreversible structural changes. Our data would suggest that recovery of left ventricular function is less likely when the left ventricular z-score has reached the value of 4, and that, ideally, intervention should be performed when the z-score approaches or exceeds 3.