Aim: The present study presented as a comparison of the cognitive functions, psychomotor performance and attention deficit hyperactivity disorders between dyslexic and control students. Method: This was a randomized study. The participants were 33 dyslexic students and 34 age, gender, and IQ-matched control students. The major evaluation tools included were Stanford Binet fourth edition for cognitive function, Quick neurological screening scale for learning disabilities, Behavioral Characteristics Rating Scales for Learning Disabilities, three Arabic standardized scales for reading and comprehension and two scales for attention deficit hyperactivity disorders (ADHD). Results: Comparisons of the 2 groups of students revealed that significantly impairment of some cognitive functions as verbal reasoning, abstract visual reasoning, short term memory and intelligent quotient. Also, impairment of psychomotor performance and higher scores of ADHD were detected among dyslexic group than control group. Conclusion: Association between dyslexia and ADHD are accompanied with more deterioration in some cognitive functions and psychomotor performance.