Interest in school science and technology (S&T) remains an important issue as it is linked to achievement and the intention to pursue studies or careers in S&T. Around the world, a number of studies have shown that interest in S&T declines with school years. However, some divergences from the general trend have been demonstrated in certain contexts, sub-periods, or for closely related subconstructs. We administered 2,628 questionnaires to students in grades 5 through 11 in the province of Québec, Canada. The questionnaire explored many factors (including out-of-school and school-related preferences, difficulty, importance, frequency), allowing us to track these closely related variables for a seven-year period. Among others, the results show a general degradation in-school S&T factors but an improvement in out-of-school S&T variables and of interest in S&T studies and careers. S&T is perceived as increasingly difficult and valuable compared with all other subject matters taken one-on-one. Some shorter fluctuations are analysed and interpreted in comparison with the evolution of certain teaching practices.