The cortical activation and performance of 3rd grade students were investigated using Functional near infrared spectroscopy (fNIRS) during reading Arabic language. The main cortical activation parameter tested was hemoglobin difference (HbDiff), while the performance was evaluated according to the number of committed errors and latency. The recorded HbDiff concentrations for the typically developed (TD) were significantly higher (0.05) than that of students with dyslexia (Dys), confirming higher brain activities for TD students. TD students committed less errors and need less time to finish the task. Moreover, Pearson correlation analysis performed showed that there was a negative correlation between cortical activation parameters and performance. Limited studies explored the use of fNIRS to investigate the cortical activation of Arabic students' brains or correlated between the cortical activation and performance variables. Therefore, this current research is novel and showed the potential utilization of the fNIRS in the field of educational neuroscience.