Background: Previous research has revealed the existence of gender differences in physical education. Most descriptive studies show that boys are more physically active than girls, have greater self-perception of enjoyment and competence in physical education, attach more importance to sports and participation in them and demonstrate higher game performance in invasion games. There also exist different participation and learning patterns. Experimental studies have shown that with the correct methodology some of these differences can be modified and that stereotypes are dynamic and depend to a large extent on the interactions that occur during the learning process. Purpose: It was the purpose of this study to evaluate possible gender differences in the game behaviour of physical education students in terms of participation and offensive tactical behaviour in invasion games with mixed teams. Methods: The participants were boys (n = 31) and girls (n = 43) in four age groups (primary years two, four and six and secondary year two; aged 7-8, 9-10, 11-12 and 13-14 years). Offensive game behaviour was evaluated during game play through the number of attacker-on-the-ball actions (AonBA; passes, movements on the ball and shots), and the percentage of offensive actions related to a specific offensive tactical intention (OTI; keeping the ball, penetrating the defense, scoring and spectator-player). Students were evaluated through a modified invasion game, where the technical and rules requirements were minimised and adjusted to the developmental characteristics of the participants. Results: The results showed that boys participated more in offensive play with the ball, especially in the number of movements on the ball (boys, M= 10.5; girls, M = 6.4; p less than 0.01) and shots (boys, M = 3.3; girls, M = 1.2; p less than 0.01). Analysis of OTI revealed differences in intention to score (boys, M = 6.1%; girls, M = 3.5%; p less than 0.01) and in actions such as spectator-player (boys: 3.1; girls: 6.4; p less than 0.05). In analysis by age groups the greatest differences were detected in the oldest group. Conclusions: The results confirmed the existence of stereotypical forms of participation in invasion games. The boys focused on handling the ball and achieving the goal, while the girls displayed more off-the-task (spectator-player) behaviours. The results were consistent with most studies demonstrating gender behaviour in physical education, with differences increasing in adolescence. (Contains 4 tables.)