Hypertension is common in hemodialyzed patients and constitutes an important cardiovascular risk factor. Fluid retention, inappropriate stimulation of the renin-angiotensin system, sympathetic overactivity and changes of vessel wall structure have been shown to be important factors in its pathogenesis. It has been claimed that hemofiltration permits a better control of hypertension in the interdialytic interval, although the evidence is not perfectly convincing; blood pressure tends to be lower with continuous ambulatory peritoneal dialysis. While fluid withdrawal and – within certain limits – adjustment of dialysate sodium concentration constitutes a primary line of therapy, antihypertensive medication is necessary in approximately 20% of patients. Specific problems with dialysis patients are cumulation of drugs (some cardioselective beta-blockers, alpha-methyldopa, captopril), altered dose-response relationship (diuretics) and particularly interaction with cardiovascular stability during fluid withdrawal.