Aim To investigate the effects of rosiglitazone on left ventricular hypertrophy in 5/6 nephrectomized rats. Methods Chronic renal failure of rats was induced by 5/6 nephrectomy.Then the inhibiting development of left ventricular hypertrophy(LVH) mechanism of the rats was explored by observing the nephrectomized rats which were randomly allocated into four groups: XL group(rosiglitazone treatment,5 mg/(kg·d)),DL group(rosiglitazone treatment,15 mg/(kg·d)),model group and sham group,in which the rats with sham operation served as control.5 mg/kg rosiglitazone,15 mg/kg rosiglitazone were respectively delivered daily via gavage for a period of eight weeks.The urinary protein,blood urea nitrogen(BUN),serum creatinine(Scr),blood pressure(BP),angiotensin Ⅱ(AngⅡ),endothelin(ET),body weight(BW),left ventricular weight(LVW) and LVW/BW were measured at the end of the study.Left ventricular hypertrophy was accessed by pathological analysis,and myocardium collagen fibers were stained with Picric acid-Sirius red. Results Compared with model group,the blood pressure of rats in XL group and DL group substantially decreased(P<0.01).So was the case with 24 hours urinary protein,Scr,BUN and plasma AngⅡ,ET.Compared with sham group,the ratio of left ventricle weight to body weight as well as collagen expressions of the left ventricular myocardium in the model group significantly increased(P<0.05).Compared with model group,the above parameters in DL group significantly decreased(P<0.01). Conclusion Rosiglitazone can obviously lower the blood pressure,reduce 24 hours urinary protein,BUN,Scr and recover renal historical damage,regress left ventricular hypertrophy,attenuate remodeling of myocardial collagen network in rats with chronic renal failure.The effect of rosiglitazone is possibly mediated by AngⅡ and ET.