[Increased screen hours are associated with low school performance]

To analyze whether screen time is related to lower academic performance in second-cycle students and to determine differences by sex.

Analytical, retrospective, and cross-sectional research. 733 students from the 5th to 8th year of public schools participating in the study "school health and performance survey in the Biobío province 2018" were recruited. The use of the screen was self-reported through daily hours in front of the TV, video games, and the internet. School performance was measured with the report card of reading, math, physical education, and the grade point average and through behaviors related to cognition in the school context. To determine the relationship between screen time and school performance, the Pearson's correlation coefficient was determined, and to measure the influence of sex and screen hours on the grades, a two-way ANOVA was performed.

The students spend 6.1 ± 5.3 hours in front of a screen daily. Boys spend more time playing video games and girls surfing the internet. Both boys and girls who spend more hours in front of a screen, mainly playing video games and surfing the internet, presented lower grades in mathematics, reading, physical education, grade point average, and had less memory, were slower in solving mathematical problems and had more difficulties in maintaining attention in class or solving complex tasks.

Screen use is negatively associated with academic performan ce, as well as behaviors related to cognition in students of both sexes.