Background and Aim: Reading is undoubtedly an essential skill for everybody in these years. Reading disorders or dyslexia can cause several problems for those who suffer from them. Early assessment and diagnosis play an important role in treatment of this disorder. The main aim of this study was determining the prevalence of reading disorder in first to fifth grade elementary school students. The subbasic aim was introducing the screening Inventory Reading Test (IRT) for diagnosis of the Students with reading disorder at elementary schools.

Methods: A total of 200 students (boys and girls) in five elementary education grades in Isfahan were selected through multi-stage random sampling method and assessed by IRT in 2008. Descriptive statistical analysis was performed using SPSS Software package version 13.0 for Windows.

Results: This survey revealed the highest prevalence of reading disorder in the first grade male students (25%), and the lowest in fifth grade female students (0%). The incidence of dyslexia in all grades generally was 10%. The overall incidence was 66% for male students and 34% for female students.

Conclusion: Reading disorder is more prevalent among male students than female students and the Inventory Reading Test is a satisfactory tool for rapid diagnosis of reading disorder.