In this meta-analysis, because of the prognostic value of methylation status of MGMT promoter by PSQ for survival of GBM patients unclear and no in consensus, we summarized relevant data to quantify the prognostic value of methylation status of MGMT promoter by PSQ, using standard meta-analysis techniques, regardless of impact factors, such as age of patients, therapy modality, etc. This evidence concerns the gene MGMT and glioblastoma.