Fluent reading is a multifaceted ability that integrates several linguistic and non-linguistic processes. Accordingly, recognizing the critical components of fluent reading is highly significant in planning and implementing effective reading programs. This study was undertaken to evaluate the predictive power of syntactic knowledge, vocabulary breadth, and metacognitive awareness of reading strategies in the reading fluency of Iranian EFL learners. To this end, a sample of 149 Iranian EFL language learners took the Vocabulary Levels Test, Survey of Reading Strategies Questionnaire (SORS), a TOEFL PBT, and a fluency test. The linear regression results indicated that vocabulary breadth was the first predictor of readers' performance on reading fluency, followed by metacognitive awareness of reading strategies. At the same time, syntactic knowledge was not entered into the regression model. Moreover, the findings confirmed the contribution of both linguistic and non-linguistic processes to reading fluency. Having a clear picture of fluency components can be advantageous to teaching reading comprehension and test score predictability.
