More than 40% of patients hospitalized with heart failure have preserved left ventricular ejection fraction (HF-PLVEF) and are at high risk for cardiovascular (CV) events. The purpose of this study was to determine the value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and brain natriuretic peptide (BNP) in predicting CV outcomes in patients with HF-PLVEF. Participants with an ejection fraction >40% in the prospective CHARM Echocardiographic Substudy were included in this analysis. Plasma NT-proBNP levels were measured, and 2 cut-offs were selected prospectively at 300 pg/ml and 600 pg/ml. BNP cut-off was set at 100 pg/ml. Clinical characteristics were recorded, and systolic and diastolic function were evaluated by echocardiography. The primary substudy outcome was the composite of CV mortality, hospitalization for heart failure, and myocardial infarction or stroke. A total of 181 patients were included, and there were 17 primary CV events (9.4%) during a median follow-up time of 524 days. In a model including clinical characteristics, echocardiographic measures, and BNP or NT-proBNP, the composite CV event outcome was best predicted by NT-proBNP >300 pg/ml (hazard ratio 5.8, 95% confidence intervals [CI] 1.3 to 26.4, p = 0.02) and moderate or severe diastolic dysfunction on echocardiography. When NT-proBNP >600 pg/ml was used in the model, it was the sole independent predictor of primary CV events (hazard ratio 8.0, 95% CI 2.6 to 24.8, p = 0.0003) as was BNP >100 pg/ml (hazard ratio 3.1, 95% CI 1.2 to 8.2, p = 0.02) in the BNP model. In conclusion, both elevated NT-proBNP and BNP are strong independent predictors of clinical events in patients with HF-PLVEF.