Clinical practice guidelines (CPGs) play an important role in healthcare. The guideline development process should be precise and rigorous to ensure that the results are reproducible and not vague. To determine the quality of guidelines, the Appraisal of Guidelines and Research and Evaluation (AGREE) instrument was developed and introduced. The aim of the present study was to assess the methodological quality of clinical practice guidelines on glioma. Eight databases (including MEDLINE and Embase) were searched till to August, 2013. The methodological quality of the guidelines was assessed by four authors independently using the AGREE II instrument. Fifteen relevant guidelines were included from 940 citations. The overall agreement among reviewers was moderate (intra-class correlation coefficient = 0.83; 95% confidence interval [CI], 0.66-0.92). The mean scores were moderate for the domains "scope and purpose" (59.54) and "clarity of presentation" (65.46); however, there were low scores for the domains "stakeholder involvement" (43.80), "rigor of development" (39.01), "applicability" (31.89), and "editorial independence" (30.83). Only one third of the guidelines described the systematic methods for searching, and nearly half of the (47%) guidelines did not give a specific recommendation. Only four of 15 described a procedure for updating the guideline; meanwhile, just six guidelines in this field can be considered to be evidence-based. The quality and transparency of the development process and the consistency in the reporting of glioma guidelines need to be improved. And the quality of reporting of guidelines was disappointing. Many other methodological disadvantages were identified. In the future, glioma CPGs should be based on the best available evidence and rigorously developed and reported. Greater efforts are needed to provide high-quality guidelines that serve as a useful and reliable tool for clinical decision-making in this field.