Background: Studies demonstrate that occupational optimism can boost adolescents' academic attainment and perseverance in education. To contribute to this literature, we consider two hypotheses. The first posits that bilingual immigrants are remarkably resourceful and determined. Thus, they are more occupationally ambitious than their peers. The second proposes that immigrant students engage in "strategic adaptation" by specializing in science, viewed as a level playing field. Methods: To assess these hypotheses at two points of time, we analyze data from 19 societies that participated in the Programme for International Student Assessment (PISA) in 2006 and 2015. Our primary method is path analysis with balanced replicate weights (BRR) undertaken separately for each country's data. Results: We find that, in many countries, bilingual immigrants expect to enter higher status occupations than non-immigrants. However, immigrants who do not speak another language are also optimistic, so linguistic resources cannot explain occupational ambition. Furthermore, immigrants accord science more instrumental value and enjoy it more at school, which accounts, across societies, for up to 12% of the variation in vocational optimism indicated by the expected occupational status, and up to 41% in plans to pursue a career in science professions. Conclusion: Our results align with the "strategic adaptation" argument that many young immigrants might seek to specialize in science as a pragmatic tactic to ensure high occupational attainment.