["Scandinavian Journal of Psychology, EarlyView. ", "\nABSTRACT\nStudents' well‐being is a critical concern due to its significant implications for university adjustment and long‐term outcomes. Recurrent results of low well‐being levels highlight the need for comprehensive research to uncover its psychological mechanisms. This study examines the relationship between basic psychological needs fulfillment and affective states in explaining subjective well‐being, grounded in a novel framework: the macro‐theory of positive functioning. A sample of 1552 French students (1209 women) aged 18 to 25 completed an online questionnaire assessing well‐being, positive and negative affect, and satisfaction/frustration related to the needs for autonomy, competence, and relatedness. Path analyses supported the theoretical hypotheses: satisfaction of the three basic psychological needs positively predicted well‐being via positive affect, while their frustration did so through negative affect. Only satisfaction and frustration of autonomy exhibited direct paths to well‐being. Gender comparisons revealed that these pathways differed between men and women, a finding reinforced by strict measurement invariance. The discussion explores the integration of positive functioning and self‐determination theory, emphasizing their interconnectedness and outlines practical implications for enhancing students' well‐being.\n"]