Background: Oxidative stress and adipocytokines are reported to contribute to the pathogenesis of atherosclerosis. Though the inhibition of the renin-angiotensin system is known to have beneficial effects on atherosclerosis, the exact mechanisms for this remain to be clarified. The aim of this study was to determine the effects of angiotensin II receptor blockers (ARB) on the oxidative stress and adipocytokines in peritoneal dialysis patients. Methods: Candesartan (8 mg/day), an ARB, was administered for 3 months to 8 nondiabetic patients on peritoneal dialysis. Plasma levels of advanced oxidation protein products (AOPP) and adiponectin were measured before and 3 months after candesartan administration, and 3 months after discontinuation. Results: Plasma AOPP level decreased from 377.5 to 305.6 µmol/l (p < 0.05) following the administration of candesartan and returned to 394.6 µmol/l (p < 0.05) by 3 months after the discontinuation of the drug. Plasma adiponectin level increased from 12.5 to 18.8 µg/ml (p < 0.05) by candesartan and decreased again to 14.4 µg/ml (p < 0.05) after discontinuation. There was a significant inverse relationship between changes in plasma level of adiponectin and AOPP (r = – 0.888, p < 0.01). Conclusion: Candesartan increases plasma adiponectin level in association with the reduction of oxidative stress in peritoneal dialysis patients. Candesartan may be useful in preventing atherosclerosis in peritoneal dialysis patients.