Whereas left ventricular systolic function has been shown to predict outcome in hypertensive patients without clinical evidence of heart failure, the prognostic power of diastolic function has not been examined. We assessed the relation of mean pulmonary capillary wedge pressure as an index of left ventricular diastolic function to mortality and the incidence of cardiovascular events in patients with uncomplicated hypertension at baseline. Invasive hemodynamic measurements were performed in the period 1972 to 1982 in 172 hypertensive patients without evidence of cardiovascular disease, cardiomegaly or heart failure, and their outcome was ascertained in 1994. Age at baseline averaged 37 +/- 12 years, brachial artery pressure was 162 +/- 30/88 +/- 18 mm Hg, and mean pulmonary wedge pressure 6.3 +/- 3.0 mm Hg. During 2675 patient-years of follow-up, 15 patients died and 34 suffered at least one fatal or nonfatal cardiovascular event. Cox regression analysis showed that pulmonary wedge pressure was a significant predictor of total mortality and of cardiovascular events, after control for age and gender (P < .05). Each 1 mm Hg increase in wedge pressure was associated with a 23% increase in the risk of all-cause mortality and a 13% increase in the risk of a cardiovascular event. The prognostic power was independent of mean brachial artery pressure, body mass index, serum cholesterol, electrocardiographic left ventricular hypertrophy, and smoking at baseline. We conclude that mean pulmonary wedge pressure, which is likely to reflect left ventricular diastolic function in the selected patients of the current study, is a significant and independent predictor of mortality and of cardiovascular events in uncomplicated hypertension.