Background: Academic buoyancy (Martin & Marsh, 2006, "Oxford Review of Education," 35, 353; 2008, "Journal of School Psychology," 46, 53) is students' competence to respond effectively to academic daily setbacks and is considered an optimal characteristic of students' functioning related to achievement. From the self-determination theory perspective (Ryan & Deci, 2017, "American Psychologist," 55, 68), satisfaction of the need for autonomy, competence, and relatedness and autonomous forms of motivation relate to students' optimal functioning in schooling. Aims: We investigated (1) whether students' end-of-course (T2) academic buoyancy in the normative environment of English preparatory programmes (EPP) is predicted by their beginning-of-course (T1) need satisfaction or frustration and autonomous or controlled motivation (i.e., high or low self-determined motivation), and (2) whether students' T2 academic buoyancy mediates the relation between students' T1 self-determined motivation and final (T3) academic achievement. Sample: In T1 and T2, 267 students (M[subscript age] = 19.11, SD = 1.28) attending three EPPs in Ankara, Turkey, participated in the study. Method: A prospective design was used, data were collected through self-reports, and SEM was conducted to test the hypotheses. Results: Students' T1 need frustration negatively predicted T1 autonomous motivation and positively predicted T1 controlled motivation, which (respectively) positively and negatively predicted T2 academic buoyancy. T1 need satisfaction related positively to T2 academic buoyancy. Finally, T2 academic buoyancy mediated the relation between students' need satisfaction and final achievement while controlled motivation was also negatively related to final achievement. Conclusion: Students' high need satisfaction and low need frustration as well as high autonomous and low controlled motivation could support students' buoyancy and achievement in the normative settings of EPP.