Angiotensin-converting enzyme inhibitors (ACEIs) were accepted as a potential cause of inadequate epoetin response in chronic kidney disease (CKD) patients. We aimed to determine the effects of valsartan, an angiotensin receptor blocker (ARB), on serum ertyhropoietin levels and on certain biochemical and haematological parameters in hypertensive CKD patients. Twenty-two stage III-IV CKD patients (mean age; 56.8 +/- 8.9 years, 12 male 10 female) were included in the study. Before initiating the treatment, current anti-hypertensive treatments (if any) were discontinued, and blood samples were collected after a washout period of 3 weeks. Valsartan 80 mg/day was started, and additional anti-hypertensive agents were given according to study protocol if needed. One way Anova and paired t-tests were used for statistical comparisons. Serum blood urea nitrogen (BUN), creatinine, uric acid, potassium, haemoglobin and erythropoietin values were measured, and glomerular filtration rates were calculated before and 3, 6 and 90 days after valsartan treatment, a significant reduction in EPO level was observed at 3rd (19.6 +/- 24.0 vs. 13.8 +/- 8.5, p = 0.010), 6th (12.1 +/- 7.6, p = 0.009), and 90th days (8.3 +/- 5.4, p = 0.007). When pre-treatment values were compared with 90th day results, no significant change was observed in terms of hgb, htc, serum BUN, creatinine, uric acid, potassium, and GFR values. In conclusion, valsartan, an ARB, did not decrease haemoglobin levels In stage III-IV CKD patients despite significant reduction in serum erryhropoietin levels, so ARBs may be preferred to ACEIs in CKD patients when indicated.