This study investigated the relationship between student performance on behavioral measures (reading, language, and executive function) and reading comprehension while reading with and without text-to-speech (TTS) accommodations. Twenty-nine children with reading difficulties ages 8 to 12 years completed a battery of reading, language, and executive function measures. They read 5 passages and answered comprehension questions under the following conditions: (a) silent reading, (b) reading aloud, (c) listening with digitized speech only, (d) reading with the use of TTS with no highlighting, and (e) reading with the use of TTS with highlighting. We used a principal component analysis and a mixed-effects logistic regression model. Language/Reading was a significant predictor of comprehension in both TTS conditions, whereas Executive Function was a strong predictor of comprehension in the listen only and silent reading conditions. Implications of language proficiency and executive function for successful use of TTS to support reading comprehension warrant further investigation.