This paper presents results of a study conducted with undergraduate students involved in either problem- or project-based curricula (Medicine and Engineering, respectively) at the Université de Sherbrooke, Canada. The objective of the present research was to measure the impact of these innovative curricula on students' engagement and persistence in higher education. Our research question was: What determinants better predict students' engagement and persistence in innovative curricula such as PBL? Nine variables were examined as potential predictors of both factors (engagement and persistence). Results showed a variation in variables predicting engagement and persistence, with the most significant predictor being stress related.