Introduction of the Teaching Games for Understanding (Bunker & Thorpe, 1982) approach has stimulated a debate on the efficacy of differing pedagogical approaches in delivering games within physical education. Much of this debate has centered around the comparison of skill-drill to tactical approaches and their relative effects on cognitive and behavioral student outcomes (Turner & Martinek, 1999). Holt, Strean & Bengochea (2002) highlighted the paucity of attention to the affective consequences of differing pedagogical approaches. Affective responses such as enjoyment and perceived effort may be important factors in determining student's future involvement in sport and games (Scanlan & Simons, 1992). The purpose of this study was to investigate the effect of the tactical games approach (Griffin, Oslin, & Mitchell, 1998) on students' motivational responses in games-based physical education. Participants were 248 students (130 boys and 118 girls) aged between 10 and 16 years, from 11 different schools within an urban school district. All 13 classes of students participated in a unit of games-based physical education taught using the tactical games approach and delivered by their regular physical education teacher. Pre- and post-intervention measures of student enjoyment, perceived effort, perceived competence, and perceptions of dimensions of the learning environment (perceived challenge, threat, organization, competition and choice) (PELES, Mitchell, 1996) were obtained for all students. Using group as the unit of analysis (N=13), a repeated measures multivariate analysis of variance of motivational indices (enjoyment, effort, perceived competence) yielded a significant main effect for time (p<.001,h2=.55) and gender (p<.05, h2=.38). There was no significant interaction between gender and time. Follow-up univariate tests indicated that the mean level of enjoyment and perceived competence increased over time. Univariate tests of between-subjects variance revealed that gender effects were explained by significant differences in perceived competence. Multiple regression analyses revealed that increases in perceived challenge explained a significant amount of unique variance in the students' post-intervention enjoyment, perceived effort and perceived competence responses. The results suggest that the pedagogy of the tactical games approach seemed to foster a non-threatening level of challenge to students such that the students enjoy the experience of mastering the tactical dimensions of the game and are motivated to engage within games-based activities. Given the research, (e.g. Telama, 1998) which has shown a significant positive relationship between perceived competence and continued participation in physical activity, the tactical games approach may have the potential to motivate students to continue with physical activity outside-of-school.Keyword(s): curriculum development, research, student issues