Background: The accuracy of surgical scores in predicting in-hospital mortality for nonsurgically treated patients with infective endocarditis (IE) has not yet been explored.Methods: Patients with definite IE who did not undergo valve surgery were selected from the database of seven French administrative areas (Association pour l'Étude et la Prévention de l'Endocardite Infectieuse [AEPEI] Registry, 2008). The patients were scored using (a) six systems specifically devised to predict in-hospital mortality after surgery for IE, (b) three commonly used risk scores for heart surgery, and (c) a risk score for predicting six-month mortality in IE after either surgery or medical therapy. Calibration (Hosmer-Lemeshow test) and discriminatory power (receiver operating characteristic [ROC] analysis) were assessed for each score. Areas under ROC curves were compared one-to-one (Hanley-McNeil method).Results: A total of 192 patients (mean age, 65.2±15.2 years) were considered for analysis. There were 38 (19.8%) in-hospital deaths. Age >70 years (p=0.001), Staphylococcus aureus as causal agent (p=0.05), and severe sepsis (p=0.027) were independent predictors of in-hospital mortality. Despite many differences in the number and type of variables, all but two of the investigated scores showed good calibration (p>0.66). However, discriminatory power was satisfactory (area under ROC curve >0.70) only for three of the scores specific for IE and two of the scores used to predict mortality after cardiac surgery.Conclusions: Among the 10 surgical scores evaluated in this study, five could be adopted to predict in-hospital mortality even for IE patients receiving medical treatment only.