Objective To observe the impact of angiotensin II receptor blocker Losartan on insulin resistance and dialysis adequacy in continuous ambulatory peritoneal dialysis (CAPD) patients, and to evaluate the correlation of serum adiponectin (ADPN) to insulin resistance and dialysis adequacy. Method We recruited 25 CAPD patients treated in this hospital and randomly divided them into two groups: peritoneal dialysis (PD) group (N=12) and Losartan+PD group (N=13). Eight end stage renal disease (ESRD) patients without dialysis were used as the control group. The homeostasis model assessment-insulin resistance index (HOMA-IR), blood lipids, residual renal function and dialysis adequacy were evaluated at 0, 3 and 6 months after the treatment. Result In Losartan+PD group, HOMA-IR, triglyceride, cholesterol and low density lipoproteins (LDL) were decreased, whereas total Ccr, peritoneal Ccr, total Kt/V and peritoneal Kt/V were increased, as compared with those in PD group and control group. Serum ADPN was positively correlated to triglyceride, cholesterol and LDL, and negatively correlated to peritoneal Ccr and peritoneal Kt/V. Conclusions Losartan improves insulin resistance and dialysis adequacy, and decreases serum ADPN levels in CAPD patients. Serum ADPN positively correlates to triglyceride, cholesterol and LDL, and negatively correlates to peritoneal Ccr and peritoneal Kt/V.