Background: Determining refractive errors among general education school students by age and gender Methods: The study was conducted using a cross-sectional model based on the examination records of 5,202 students from School No. 24 and School No. 37 by the ophthalmologist of the Chingeltei District Health Center in Ulaanbaatar. Results were analyzed SPSS. Result: The average age of all students included in the study was 11.37 ± 3.27 years. Among the participants, 62% (n = 3,208) were from School No. 24, and 38% (n = 1,994) were from School No. 37. Of the students from School No. 24, 18.6% (n = 597) had refractive errors. Specifically: Myopia was present in 17.2% (n = 552), with 6.1% male and 11.1% female. Hypermetropia was found in 0.68% (n = 22), with 0.43% male and 0.25% female. Astigmatism was detected in 0.72% (n = 23), with 0.34% male and 0.38% female. From School No. 37, 6.23% (n = 200) of students were diagnosed with refractive errors. Specifically: Myopia affected 5.23% (n = 168), with 1.96% male and 3.27% female. Hypermetropia was found in 0.16% (n = 5), with 0.07% male and 0.09% female. Astigmatism was present in 0.84% (n = 23), with 0.28% male and 0.56% female. There is a very weak negative correlation between myopia and age, as well as between myopia and gender, which is statistically significant. There is also a very weak negative correlation between astigmatism and age, which is statistically significant. Conclusion Our study found that among the types of refractive errors, myopia was the most common, with female students being more susceptible compared to males. The two schools included in the study represent both central (School No. 24) and peripheral (School No. 37) areas of Ulaanbaatar. Refractive errors were found to be more prevalent among students from the central school (School No. 24).