Students’ school-related well-being (SWB) is of vital importance. Nevertheless, it is unclear how SWB develops in late adolescence, especially among students in high-achieving environments and which factors are associated with it. Based on a longitudinal dataset (T1: Grade 11, T2: Grade 12), we analyzed how SWB (school satisfaction, academic self-concept, stress experience, exam anxiety, peer satisfaction) develops and whether psychological needs (autonomy, competence, relatedness) and achievement pressure from teachers and parents were related to the development. 1,286 students from high-achieving high schools (46.7% female, MageT1 = 16.40) answered sociodemographic questions and questions about key variables. From T1 to T2, particularly students’ stress experience and peer satisfaction declined. Need fulfilment and perceived achievement pressure was related to changes. Implications for research and practice are discussed.