This article presents an analysis of the evolution of adolescents’ motivation within the school context. Comparisons are made according to gender and schooltracks. The study was carried out with 332 pupils of grade 7 through 9 who were asked to posit themselves on four dimensions of the Multidimensional scale of motivation for the school context (EMMAS, Ntamakiliro, Monnard & Gurtner, 2000), namely learning intention, subjective competence, school attractiveness and test anxiety. Our results show that if motivation globally declines over the three years, differences in these evolutions appear according to gender and track. An interaction effect between these three variables can even be seen regarding subjective competence. These results confirm the importance of taking into account these three parameters in order to understand pupils’ motivation and to sustain it during the critical phase of adolescence.