The aim of this empirical research is to verify the contribution of proactivity and different learning approaches to students’ academic achievement. Furthermore, it investigates the mediating role of different learning approaches (deep, surface and strategic) in the relationship between proactivity and academic achievement. Data was collected by surveying a large sample of undergraduate students of different orientations and analyzed with path analysis within the structural equations modeling. In line with the assumptions of the proposed model, the results confirm the positive impact of proactivity on deep and strategic learning approaches and a negative relationship between proactivity and use of surface learning approach. Furthermore, a strategic approach positively contributes to the students’ academic achievement, while the surface approach has a negative contribution. The deep learning approach has no direct effect on the students’ academic achievement. However, the deep approach, through the strategic approach, indirectly positively affects students’ academic achievement. Also, the results confirmed the mediating role of strategic and surface learning approaches in the relationship between proactivity and academic achievement, which demonstrates that students’ proactivity, indirectly, through these learning approaches, positively contributes to the students’ academic achievement. Specifically, higher degree of proactivity will result in selecting effective learning approaches, which will further lead to a higher level of students’ academic achievement. The research findings are interpreted in the framework of the theory of self-regulated learning and the concept of students’ approaches to learning. The importance and ways of implementation of the results in an academic context are discussed.