Objective To assess the clinical efficacy of Cordyceps sinensis in the treatment of chronic kidney diseases. Methods Randomized or quasi-randomized controlled trials (RCTs or quasi-RCTs) were identified from MEDLINE (1996 to Oct. 2005), EMbase (1984 to Oct. 2005), The Cochrane Central Register of controlled Trials (Issue 3, 2005) and CBMdisc (1978 to Oct. 2005). We also handsearched related published and unpublished data and their references. Data were extracted and evaluated by two reviewers independently with a designed extraction form. RevMan4.2.7 software was used for data analysis. Results One RCT and 5 quasi-RCTs involving 434 patients were included. Results of meta-analysis were presented as follows: ① Response rate: five studies showed that, compared with the blank control group, significant differences were observed after the treatment with Cordyceps (RR 2.13, 95%CI 1.06 to 4.26); one study showed that there was no difference between Cordyceps and Shenyankangfu tablet (RR 2.17, 95%CI 0.73 to 6.460). ② Total effective rate: five studies showed that, compared with the blank control group, significant differences were observed after the treatment with Cordyceps (RR1.94, 95 %CI 1.14 to 3.30); one study showed that there was no difference between Cordyceps and Shenyankangfu tablet (RR 1.39, 95%CI 0.89 to 2.16). ③ Adverse reactions: adverse reactions were rare only with mild symptoms. Conclusions Cordyceps sinensis may improve the response rate and total effective rate of chronic kidney diseases. More high quality trials are required.