Background: Refractive errors are among the most common causes of vision loss in patients attending healthcare facilities in the first and second decades of life. Astigmatism stands out as one of the common and treatable causes of vision loss in pediatrics. 
Methods: In this cross-sectional study, the samples were chosen by random cluster sampling among children aged between 7 and 13 years from elementary schools in 2014-2015 academic year. For all students, refractive errors were assessed by Autorefractor Keratometer and retinoscopy. Internal astigmatism was defined as the difference between refractory and corneal astigmatism. SPSS software, version 16 was used for data analysis.
Results: A total of 1009 children participated in the study. Among them, 468(46.4%) were male, and 541(53.6%) were female. Their mean age was 9.2±1.7 years. About 14.5% of them had refractory astigmatism. Corneal astigmatism was the most common type, with 12.5% of students suffering from it. The prevalence of corneal astigmatism was not significantly different between males and females (P=0.19). Also, there was no significant relationship between increasing age and prevalence of astigmatism in this age group (P=0.06).
Conclusions: There was no significant difference in the rate of refractory astigmatism, lenticular and corneal astigmatism, between males and females. Because correcting refractory errors in students has a positive effect on learning ability and physical and mental development, screening and follow-up are recommended in this age group.