Background: Paravalvular abscess formation is ark ominous complication of infective endocarditis; however, prognostic variables in paravalvular abscess are poorly defined. Methods: We examined our experience in patients with paravalvular abscess between 1987 and 2004. Clinical, echocardiographic, microbiologic, and surgical data were examined. Results: There were 45 patients (17 females), age 57 +/- 17 years. Twenty-four patients had prosthetic valve endocarditis. Methicillin-sensitive Staphylococcus aureus and coagulase-negative S. aureus; were the most common organisms accounting for 25 (56%) cases. Thirty-eight patients (84%) underwent surgery during initial admission. Surgical mortality was 7%, in-hospital mortality was 31%, and I-year mortality was 38%. Between patients who died and patients who survived, there were no differences in age (61 +/- 20 years vs 55 +/- 15 years, P =.3), type of microorganism, presence of prosthetic heart valves (47% vs 57%), presence of moderate to severe or severe regurgitation of involved valve (47% vs 57%, P =.37), presence of associated valvular vegetation (93% vs 93%, area of abscess (5.6 +/- 2.9 cm(2) vs 4.4 +/- 3.2 cm(2), P =.39), left ventricular systolic function (56% 13% vs 56% 10%, P = .9), white cell count (13 +/- 4 vs 13 +/- 7, P = .9), or polymorphonuclear leukocytosis (86% +/- 6% vs 81% +/- 9%, P =. 1). Patients who died were sicker on admission compared with those who survived (33% had stroke or altered mental status vs 7%, P = .03) and had worse renal function compared with those who survived (creatinine 4 +/- 4 mg/dL vs 1.6 +/- 1.9 mg/dL, P = .009). Conclusion: Neurologic impairment and renal impairment are significant determinants of 1-year survival in patients who present with paravalvular abscess.