Academic stress among adolescents can undermine academic achievement and harm mental health. Levels of academic stress vary considerably across countries and education systems, but little is known regarding the causes of this variation. In this paper, I develop a theoretical framework positing that stress will be lower in education systems that reduce the stakes attached to academic achievements, temper competition and high aspirations, and weaken the link between achievements and self-worth. I test observable implications of the framework by analysing if stress is influenced by the degree of external differentiation and vocational orientation of education systems, using harmonised survey data on pupils in more than 30 countries. The empirical analyses largely support the implications of the framework: pupils in more differentiated and vocationally orientated systems report significantly lower levels of stress, also in models adjusting for country fixed effects. Moreover, academic achievement is a less important predictor of stress in differentiated or vocational systems, possibly due to lower stakes attached to achievements. I end by proposing further predictions of the framework that can be tested in future research, and by discussing implications of the results with regard to possible trade-offs between different goals of education policy.