Hypertension is a major cause of cardiac disease in patients on hemodialysis (HD) and is most commonly due to hypervolemia. Removal of excess water during HD can successfully normalize blood pressure, but its success depends on an accurate assessment of dry weight. This article reviews the literature concerning hypertension in patients on HD and proposes that increased attention by dialysis staff to assessing dry weight may reduce the incidence of hypertension and cardiac disease in these patients.