Objective: To examine the notion that playing video games is negatively related to the time adolescents spend in more developmentally appropriate activities. Design: Nonexperimental study. Setting: Survey data collected during the 2002-2003 school year. Participants: A nationally representative sample of 1491 children aged 10 to 19 years. Main Outcome Measure: Twenty-four-hour time-use diaries were collected on 1 weekday and 1 weekend day, both randomly chosen. Time-use diaries were used to determine adolescents' time spent playing video games, with parents and friends, reading and doing homework, and in sports and active leisure. Results: Differences in time spent between game players and nonplayers as well as the magnitude of the relationships among game time and activity time among adolescent game players were assessed. Thirty-six percent of adolescents (80% of boys and 20% of girls) played video games. On average, gamers played for an hour on the weekdays and an hour and a half on the weekends. Compared with nongamers, adolescent gamers spent 30% less time reading and 34% less time doing homework. Among gamers (both genders), time spent playing video games without parents or friends was negatively related to time spent with parents and friends in other activities. Conclusions: Although gamers and nongamers did not differ in the amount of time they spent interacting with family and friends, concerns regarding gamers' neglect of school responsibilities (reading and homework) are warranted. Although only a small percentage of girls played video games, our findings suggest that playing video games may have different social implications for girls than for boys.