The current research is derived from the Dualistic Model of Passion positing the existence of a harmonious (HP) and obsessive passion (OP). We propose and test a serial mediation model of educational persistence in two cross-sectional studies with first (N = 366) and second-year (N = 199) science students in college with the hypothesis that OP and HP will induce different types of persistence. In Studies 1 and 2, we hypothesized that OP would positively predict a rigid persistence, whereas HP would positively predict flexible persistence and that only those who persisted flexibly would also experience wellbeing outside of school. We also expected both types of persistence to mediate the relationship between passion for science and self-reported science grades, which in turn would lead to intentions to pursue science at university (Study 1) and future applications in STEM university programs (Study 2). Furthermore, we assumed that extracurricular scientific activities would also be positively associated with academic attainment and the pursuit of sciences in higher education (Study 2). Our hypotheses were fully supported. Additionally, only students with a HP engaged in extracurricular scientific activities which, in turn, provided a stronger prediction of science grades compared to rigid and flexible persistence.