Background and aims: Color blindness is a disease that remains undiagnosed in some cases. The diagnosis of the disease during schooling is necessary to take the required measures for the future life of adolescents. Therefore, the aim of this study was to determine the prevalence of color blindness among the students of secondary schools in Shahrekord. Methods: In this descriptive study, 4074 students of secondary schools across Shahrekord were included by the cluster sampling method. Ishihara color blindness test plate was used to diagnose color blindness. Data were analyzed using descriptive statistics (mean and percentage) by SPSS 18. Results: In general, 362 (88.8%) patients had color blindness. Out of 2052 male students and 2022 female ones, 343 (16.71%) and 19 (0.93%) cases were diagnosed with color blindness, respectively. In both genders, most students had deuteranopia or deuteranomalia, while other types of color blindness, including tritanomaly, were not detected in the students. Conclusion: The results of this study showed that the number of color blind people in the studied region was higher compared to the results of studies in the other regions of Iran. Moreover, the prevalence of color blindness was more in males compared to females. In addition, the prevalence of other kinds of color blindness mainly belonged to deuteranopia or deuteranomalia.