Purpose: To investigate the prevalence of amblyopia in children between the ages of 5-8 years based on the Korean National Health and Nutrition Examination Survey (2016). Methods: Based on the results of the Korean National Health and Nutrition Examination Survey conducted in 2016, among a total of 443 children, we measured and analyzed the visual acuities of 420 children. The visual acuity was measured using a conventional visual acuity chart. When the uncorrected visual acuity was < 0.8 in the first visual acuity test, a refraction test was performed using the automatic refraction test (KR-8800, Topcon, Tokyo, Japan) and the corrected visual acuity was measured. Unilateral amblyopia and bilateral amblyopia were defined as a ≥ 2 line difference between two eyes and visual acuity in the better eye < 0.8 or < 0.63. The significant refractive errors were defined as follows: the spherical lens was 1.5 diopters (D) or more, astigmatism was 1.0 D or more, or astigmatism of 2.5 D was 4.0 D or more. Results: The prevalence of amblyopia was 5.0% (21 patients, < 0.8 in the better eye) and 3.8% (16 patients, < 0.63 in the better eye) in a total of 420 patients (male:female = 219:201). The prevalence of amblyopia in different age groups was: 10 (10%) at 5 years of age, 6 (5.6%) at 6 years of age, 3.8% at 7 years of age, and 0.9% at 8 years of age. Nine out of 21 patients (42.9%) had significant refractive errors. The regional distribution was highest in Gangwon-do and Chungcheongnam-do provinces and parental income did not affect the prevalence of amblyopia (p = 0.189). Conclusions The prevalence of amblyopia decreased with age suggesting that early detection and treatment of amblyopia are important. Therefore, systematic eye examinations that can detect amblyopia in the early stage may be important in the National Health Care results.