This study examined the effect of playing an aggressive or nonaggressive video game on fifth-graders' free play. Twenty-two pairs of boys and 20 pairs of girls were randomly assigned to one of three conditions. One of the children in each pair played a video game rated by peers as aggressive, a video game with little aggression, or a non-video maze-solving game for 8 minutes. The other child watched. Each child was then left individually to engage in free play in a separate room for 8 minutes, and also given the opportunity to deliver rewards and punishments to another child. The results were similar for both players and observers. Girls evidenced significantly more general activity and aggressive free play after playing the aggressive video game. Girls' activity decreased and their quiet play slightly increased after playing the low aggressive game compared to the control group. Neither video game had any significant effect on boys' free play. Neither girls nor boys gave significantly more punishments or rewards after playing any of the games.