an epidemiological study was carried out to assess the prevalence of myopia among school age children of suburban population. a cross sectional and descriptive study was applied, we stratified a randomized clusters of samples, using a representative proportion of the population. There were 1138 students enrolled, including 612 boys and 524 girls. Visual acuity with Snellen card was assessed; the refractive status and corneal radius of each student were measured with an autorefractometer which did not include cycloplegic refraction. All status refractive values were confirmed by another optometrist. Specific questionnaires were used in order to collect data on the refractive condition of students. The criterion for classifying the myopia status was > or = 0.5 diopters. the mean age was 10.2 + or - 2.43 years; lower prevalence rates were found significatively in male subjects. the myopia prevalence was 33.0 %, and the probability of myopia increases with age, sex, parental history of myopia, and history of premature children and low birth weight.