The study objective was to evaluate the outcomes of surgery for active infective endocarditis with aortic root abscess formation. Between July 1996 and June 2009, 1161 patients underwent operation for aortic valve endocarditis, of whom 172 had aortic root abscess. The infected valve was native in 96 patients and prosthetic in 76 patients. Patients' mean age (± standard deviation) and logistic EuroSCORE-predicted risk of mortality were 62 ± 13 years and 23.1% ± 26%, respectively. Surgery was emergent in 96 patients (58%). The abscess involved the aortic annulus in 90 patients (52%), the intervalvular fibrous body in 81 patients (47%), and the mitral annulus in 21 patients (12%). Surgery consisted of radical resection of the abscess, reconstruction of the annulus with patches, and valve replacement. Estimated mean follow-up was 4.0 ± 0.3 years (range, 0-8.2 years). Thirty-day mortality was 25% (n = 43) (prosthetic valve endocarditis vs native valve endocarditis, 35.5% vs 16.7%, P = .005). Independent predictors of mortality were sepsis (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.2-10.7), renal insufficiency (OR, 3.3; 95% CI, 1.1-9.5), concomitant coronary artery bypass grafting (OR, 2.8; 95% CI, 1.1-7.0), and prosthetic valve endocarditis (OR, 2.4; 95% CI, 1.1-5.6). Survival at 1 and 5 years was 55% ± 4% and 50% ± 4%, respectively, and predicted by concomitant mitral endocarditis (OR, 3.2; 95% CI, 1.3-8.2), sepsis (OR, 2.7; 95% CI, 1.6-4.5), renal insufficiency (OR, 1.9; 95% CI, 1.1-3.4), and age (OR, 1.05; 95% CI, 1.02-1.07). Endocarditis recurred in 15 patients (8.7%) at a mean of 1.8 ± 2.4 years postoperatively (39 days to 6 years). The surgical treatment of aortic root abscess remains a challenge with relatively high perioperative morbidity and mortality, although long-term survival is satisfactory.