The aim of this study was to illuminate the relationships between the three components of oral reading fluency, sustained attention, working memory, and text comprehension in typically developing third-grade students (N = 140). The findings of hierarchical regression analysis reveal that speed, accuracy, and prosody together significantly explained the variance in text comprehension after taking sustained attention and working memory into account. In the final model, in which all variables were included, only prosody uniquely contributed to text comprehension. The subsequent mediation analyses revealed that prosody had a full mediating role in the relationship between working memory and text comprehension. This finding suggests that via retention of phonological information in the working memory, prosody contributes to the comprehension of the text.