Results of all major clinical trials on the efficacy of treatment of hypertension provide convincing evidence that judicious treatment of hypertension in a clinical setting and effective control of hypertension in a community setting significantly reduce the rate of morbidity and mortality from stroke. It is especially noteworthy to review the results of some of the trials on prevention of stroke mortality in the elderly. HDFP: Antihypertensive drug treatment reduced the incidence of stroke among the HDFP cohort in the age group 60-69 years as significantly as it did in the younger age group. SHEP: Treatment of isolated systolic hypertension (ISH) reduced the incidence of stroke in the SHEP cohort by 36% in five years. MRC Trial: Similar results were reported by the follow-up of the cohort enrolled in the MRC Trial. The Swedish Study: Antihypertensive treatment reduced significantly the incidence of stroke in this cohort as well.