The aim of this work is to examine the effects of a growth mindset intervention amongst first-year university students during a longitudinal study spanning over 1 month and to develop a model linking well-being and achievement variables. Growth mindset interventions, by teaching malleable instead of fixed self-conceptions, would allow students to be better equipped to face academic challenges. While previous research has focussed on academic achievement, we propose to examine the articulation between mindset and proactive coping strategies, and their impact on well-being, as well as achievement during the transition period that starting higher education, represents. Results showed a main effect of the intervention on student mindset right after the intervention delivery, but disappearing 2 weeks after; and links between growth mindset, effort attribution, mastery goals, proactive coping, stress and academic achievement. Methodological and theoretical points are discussed to improve both the intervention and the hypothesised model.