Changes in school motivation have been studied primarily as an average trend that applies uniformly to all high school students. This approach overshadows individual transitions between motivation patterns, and it does not allow for the identification of factors predicting these transitions. In this study, we tracked over a one-year period the stability of three previously identified motivation profiles ("high quantity," "moderately motivated," "poor quality") in two cultural contexts (Canada, Belgium). We also explored the role of parenting practices in predicting transitions to a better or less adaptive profile. A sample of 435 Canadian (M Age = 15.85 y.o.) and 414 Belgian adolescents (M Age = 15.19 y.o.) completed self-report measures on motivation and parent-child relationships at two time points, one year apart. Latent transition analysis indicated that the "poor quality" profile was the least stable in both samples (52.3-68.3% of stability) compared to the "moderately motivated" (72.3-73.5%) and the "high quantity" profiles (66.9-80.3%). Mover-stayer analysis showed that 66.8-73.3% of participants remained in the same profile, 16.0-19.0% moved toward a more adaptive profile, and 10.6-14.3% transitioned into a less adaptive profile. A rise in need-supportive parenting practices (autonomy support, interpersonal involvement, parental structure) predicted students' shifts to more adaptive profiles. The large amount of stability found suggests that motivation patterns are already largely crystalized in high school, but positive changes among the less motivated students remain possible given the greater malleability of their motivation patterns. Promoting need-supportive parenting practices seems a promising strategy in achieving this objective.Keywords Academic achievement motivation • High school students • Longitudinal studies • Parenting • Self-determination An alarming Gallup survey conducted among almost 1 million U.S. students from Grade 5 to Grade 12 reveals that about 33% of high school students were considered as not engaged, and an another 33% were considered as actively disengaged from their studies (Gallup, 2017). Worryingly, this survey shows that the closer students get to graduating from high school, the less enthusiastic they feel about school.