This study examined the impact of a read-aloud accommodation on standardized test scores of reading comprehension at grades 4 and 8. Under a repeated measures design, students with and without reading-based learning disabilities took both a standard administration and a read-aloud administration of a reading comprehension test. Results show that the mean score on the audio version was higher than scores on the standard version for both groups of students at both grade levels. Students with reading-based learning disabilities at both levels benefited differentially more than students with no disability. This finding continues to hold after controlling for reading fluency and ceiling effects at both grades. The results also examined the relationship between test scores and teachers' ratings of reading comprehension to determine which measures are the better predictors of teachers' ratings of reading comprehension by grade and disability classification. (Contains 3 tables and 1 footnote.)