To systematically review the efficacy/safety of radiotherapy/temozolomide (TMZ) vs. radiotherapy for treating glioblastoma (GBM), Medline, Current Contents, and Cochrane database were searched. Five studies were reviewed. Median survival ranged from 9.4 to 19.0 months (radiotherapy/TMZ) vs. 7.3-17.1 months (radiotherapy). Survival ranged from 80.2% to 95.0% (radiotherapy/TMZ) vs. 8.3-84.2% (radiotherapy) at 0.5 years and from 20.0% to 61.1% (radiotherapy/TMZ) vs. 5.0-50.6% (radiotherapy) at 1 year. Median progression-free survival (PFS) ranged from 5.5 to 13.0 months (radiotherapy/TMZ) vs. 4.4-7.6 months (radiotherapy). PFS rates at 0.5 years ranged from 53.9-78.0% (radiotherapy/TMZ) vs. 53.9-78.0% (radiotherapy). Radiotherapy/TMZ provides better survival outcomes than radiotherapy alone in treating GBM.