Background: In recent decades, adolescents and children use video games as a source of entertainment most of the time. In some children it may reach level of addiction. Video games usage may be beneficial or harmful for adolescents and children. The influence of video gaming on numerous cognitive processes is being studied more thoroughly. Objectives: To determine video games usage, assess cognitive function levels and study the relationship between adolescent video game use and cognitive function levels, Qassim region, KSA. Subjects and Methods: Research design: A cross-sectional research design was conducted at intermediate girls′ schools, Qassim region, KSA. Subjects: A multistage stratified random sampling of studied adolescents from one academic year. Setting: The study was conducted at four intermediate girls′ schools (the Sixth Intermediate girls′ school, the Ninth Intermediate girls′ school, the First Intermediate girls′ school and the Fifth Intermediate girls′ school). Tools of data collection: The Socio-demographic sheet, playing electronic games scale and Mindfulness Attention Awareness Scale were completed by 300 students. Results: Most of adolescents (75%) liking video games and (41%) practice video games every day. There was a statistically significant negative correlation between cognitive function level and video game usage (r = -0.701 and P = 0.001*). Conclusion: Video gaming was appreciated by the highest percentage of students and there was a statistically significant negative correlation between cognitive function level and video game usage. Recommendations: Developing scientific video games to assist teens in developing computer and cognitive talents that are proportional to cognitive functions. Schools should develop social activities for adolescents so they catch social skills and develop their cognitive functions instead of video games.