Background and Purpose— Despite clear evidence that blood pressure (BP) lowering is effective for prevention of cardiovascular events among patients with isolated systolic hypertension and systolic–diastolic hypertension, there is ongoing uncertainty about its effects in those with isolated diastolic hypertension. The objective of the present analysis is to determine whether BP lowering provides benefits to patients with isolated diastolic hypertension. Methods— Patients with cerebrovascular disease and hypertension at baseline (n=4283) were randomly assigned to either active treatment (perindopril in all participants plus indapamide for those with neither an indication for nor a contraindication to a diuretic) or matching placebo(s). The primary outcome was total major vascular events. Results— There were 1923 patients with isolated systolic hypertension (systolic BP ≥140 mm Hg and diastolic BP <90 mm Hg), 315 with isolated diastolic hypertension (systolic BP <140 mm Hg and diastolic BP ≥90 mm Hg), and 2045 with systolic–diastolic hypertension (systolic BP ≥140 mm Hg and diastolic BP ≥90 mm Hg) at baseline. Active treatment reduced the relative risk of major vascular events by 27% (95% CI, 10% to 41%) among patients with isolated systolic hypertension, by 28% (−29% to 60%) among those with isolated diastolic hypertension, and by 32% (17% to 45%) among those with systolic–diastolic hypertension. There was no evidence of differences in the magnitude of the effects of treatment among different types of hypertension ( P homogeneity=0.89). Conclusions— BP lowering is likely to provide a similar level of protection against major vascular events for patients with isolated diastolic hypertension as for those with isolated systolic hypertension and systolic–diastolic hypertension. Clinical Trial Registration Information— This trial was not registered because patients were enrolled before July 1, 2005.