The primary purpose of this research was to conduct a quantitative review of studies reporting information on the relation between CBM reading aloud and reading comprehension tests. Furthermore, this study examined moderators affecting the variability in the relation between CBM reading aloud and reading comprehension tests. After computer-based information searches, an extensive hand search, an ancestral search were conducted, and after exclusion criteria were applied, the present meta-analysis contained a total of 250 correlations from 55 studies. This study showed that the estimated average correlation between CBM reading aloud and reading comprehension tests was .75 ( SE = .02), with a range of .71 to .79. Compared with Cohen’s (1992) threshold, the magnitude of the overall estimated average correlation between CBM reading aloud and reading comprehension tests was large. However, this study also showed that there was statistically significant variability between and within the studies used in the meta-analysis. The findings of significant variability in the unconditional model led to a series of conditional level-three meta-analyses that included potential moderators. Proportion of students with disabilities, retelling as a response format, CBM maze as a reading comprehension test, and the time difference between CBM reading aloud and reading comprehension tests were statistically significant components affecting the strength of the relation between CBM and state achievement tests. Educational implications for teachers and researchers, limitation, and directions for future research are presented.