Isolated systolic hypertension is the predominant type of hypertension in the elderly and is associated with cardiovascular complications such as stroke, coronary heart disease and heart failure. In this review, the role of arterial stiffness, endothelial function, atherosclerosis and oxidative stress in the pathogenesis of isolated systolic hypertension is extensively discussed. Placebo-controlled intervention trials such as the Systolic Hypertension in Europe Trial and the Systolic Hypertension in the Elderly Program have clearly shown that pharmacological treatment of isolated systolic hypertension improves outcome in the elderly. Nevertheless, isolated systolic hypertension remains the major subtype of untreated and uncontrolled hypertension.