Aims and Methods: Our aim was to evaluate the antihypertensive efficacy and tolerability of angiotensin II type 1 (AT<sub>1</sub>) receptor antagonists. Valsartan or candesartan cilexetil was administered to 11 dialysis patients with elevated blood pressure. The patients (6 male, 5 female; mean age ± SD 61±11 years) were on regular bicarbonate hemodialysis three times weekly for more than 3 months using acrylonitrile and sodium methallyl sulfonate copolymer (AN69) dialysis membranes. Results: Within 252 days after administration of the AT<sub>1</sub> receptor antagonists the systolic blood pressure was significantly reduced from 161±13 to 130±12 mmHg (p<0.001), whereas the diastolic blood pressure did not change significantly (76±8 vs. 71±8 mmHg; p>0.05). In addition, heart rate (75±7 vs. 80±8/min), body weight, and laboratory variables (hemoglobin, creatinine, blood urea nitrogen, serum potassium, serum sodium, serum calcium, and total protein) showed no significant changes. During 1,188 hemodialysis sessions using AN69 membranes, no hypersensitivity reactions occurred after administration of AT<sub>1</sub> receptor antagonists. Conclusion: The results indicate that once–daily administration of AT<sub>1</sub> receptor antagonists efficiently reduces the systolic blood pressure in hemodialysis patients.