['Infective endocarditis (IE) is associated with significant morbidity and mortality. Red cell distribution width (RDW) is a recently recognized biomarker of adverse outcome in a number of acute and chronic conditions.', 'To investigate the relationship between RDW and 1-year survival in patients with IE.', 'Clinical records from two tertiary centres were used to analyze data from patients with definite IE. Clinical, echocardiographic and biochemical variables were evaluated along with RDW. One-year survival status after index hospitalization was identified for each patient.', 'One hundred consecutive patients (mean age 47.8±16.7 years; 61% men) with definite IE were enrolled. According to receiver operating characteristic curve analysis, the optimal RDW cut-off value for predicting mortality was 15.3% (area under the curve 0.70; P=0.001). Forty-one patients (41%) died within 1 year; of these, 88% had RDW results>15.3%. Univariate Cox proportional-hazards analysis showed that RDW>15.3%, heart failure, renal failure, cardiac abscess, severe valvular regurgitation and presence of dehiscence were associated with increased mortality. Multivariable Cox proportional-hazards analysis revealed that renal failure (hazard ratio [HR] 3.21, 95% confidence interval [CI] 1.35-7.59; P=0.008), heart failure (HR 2.77, 95% CI 1.1-6.97; P=0.03) and RDW>15.3% (HR 3.07, 95% CI 1.06-8.86; P=0.03) were independent predictors of mortality in patients with IE.'] Does red cell distribution width predict mortality in infective endocarditis?