Background: Severe aortic regurgitation (AR) due to Behcet disease (BD) is characterized by frequent recurrence with early prosthesis failure after surgical intervention. We hypothesized that initial lesion severity evaluated by echocardiography could predict surgical outcomes. Methods: Clinical data of 21 consecutive patients (13 males, mean age 42짹11 years) with AR due to BD who underwent corrective surgery were analyzed. The appearance of the lesion severity on the preoperative echocardiogram was scored for redundant aortic valve cusp (0-1 points), pseudo-aneurysmal changes at the aortic annulus or the ascending aorta (0-3 points), and aneurysmal involvement of the interventricular septum (0-1 points). Major adverse clinical events include tri-do surgery, transplantation and cardiac death. Results: Mean echocardiographic score was 2.5짹1.4. Although initial postoperative echocardiography showed no remnant AR, repeated surgery was performed in 10 patients (48%) during clinical follow-up of 53 months (13-150 months). A total of 36 operations was done in 21 patients, which included redo (n=6), tri-do (n=3), quadri-do (n=1), and cardiac transplantation after redo (n=1). Preoperative immunotherapy was possible in 9 patients (43%) and among them 4 patients (44%) needed redo surgery. Among 10 patients who received aggressive immunotherapy after redo surgery, 4 (40%) experienced recurrence of AR. Higher echocardiographic score was associated with repeated operation (hazard ratio [HR]=2.035, 95% confidence intervals [CI]=1.120-3.699, p=0.020) and was the only independent factor associated with major adverse clinical events (HR=2.483, 95% CI=1.125-5.478, p=0.024). The overall major adverse clinical event-free survival was 70짹12% at 5 years. The best cutoff value of echocardiographic score was 4 and the event-free survival rates differed accordingly. Conclusions: Preoperative echocardiographic score for lesion severity was useful to predict surgical outcome in AR due to BD.