The present investigation, involving two cross-sectional studies, focused on the positive impact of effective functioning on achievement-related outcomes. This theoretical orientation, recently introduced (Fraillon, 2004), falls within the framework of student well-being in academic settings. Based on our preliminary research, published previously, we developed a theoretical-conceptual model that included optimism, mastery-approach goals, and motivation towards learning. We tested the hypothesized model with two comparative cohorts: Year 12 students (N = 306) and University (N = 342) students. Data were collected based on responses of Likert-scale inventories, and MPlus 7.3 was used to test the proposed 'a priori' model. Evidence ascertained indicates similar but also varying patterns in associations, for example: (i) the positive influences of effective functioning on optimism, mastery-approach goals, and motivation towards learning, (ii), the positive influences of optimism, mastery-approach goals, and motivation towards learning on academic achievement for the secondary school cohort, and (iii) the mediating mechanisms of optimism, mastery-approach goals, and motivation towards learning for the secondary school cohort, and the mediating mechanism of motivation towards learning for the university cohort.