Isolated systolic hypertension represents an important public health issue in the 1990s because of its prevalence in the elderly and its importance as a risk factor for cardiovascular morbidity and mortality. Methodologic differences may account for the wide variation between prevalence rates in studies reported. With the advent of newer methods of blood pressure (BP) assessment, such as noninvasive ambulatory BP monitoring, it may be possible to define more accurately the true population at risk. Recent data from the Systolic Hypertension in the Elderly Program has indicated a clear benefit of treatment with a reduction in total stroke of 36%, and a reduction of 25 and 32% in the combined end points of coronary heart disease and cardiovascular disease, respectively. Further studies are now required to elucidate what treatment regimens are most effective in preferentially reducing both systolic BP, without producing undesirable effects such as diastolic hypotension, and fatal and nonfatal events. One such trial is underway in Europe using a drug regimen different from that in the Systolic Hypertension in the Elderly Program. The cost implications associated with treating the population at risk are potentially large but these are now based on firm scientific evidence.