This study aimed to confirm the status of body image perception by adolescents in South Korea and identify the associated factors using the data from the 14th Korea Youth Risk Behavior Survey (KYRBS) conducted in 2018. The KYRBS is a government-approved statistical survey performed annually and an anonymous self-administered online survey conducted in middle and high school students. The data for this study were downloaded from the KYRBS web site and analyzed through complex sample analysis. Body image distortion was found in 40.3% (under-perception 26.5%, over-perception 13.8%) of the boys and 39.7% (under-perception 14.4%, over-perception 25.3%) of the girls. The factors associated with body image distortion were school achievement, weight control, school, school type and exercise in school gym class in boys and school achievement, weight control, and economic status in girls. These results indicated that intervention programs for the accurate perception of body image should be provided to adolescents and these programs should consider gender difference in factors associated with adolescents' body image distortion. •There is no difference between boys and girls in body image distortion.•Body image distortion is high in boys and girls who do not try to control their weight.•Body image distortion of boys is primarily associated with school-related factors.•Body image distortion of girls is also associated with non-school factors.