The prevalence of essential hypertension is very high in Western Countries and isolated systolic hypertension (ISH) is the peculiar form of older patients. ISH was considered a physiological condition until the '80s and it was recognised as a real disease only in the '90s, when the efficacy of pharmacological treatments in terms of cardiovascular morbidity and mortality in older patients was finally demonstrated. However, until now the cut off value for treatment as well as the efficacy and opportunity of treating the oldest old affected by significant comorbidity and disability, were controversial. In this paper the main epidemiological, physiopathological and therapeutic aspects of ISH will be reviewed.