Motivation for school is important for students’ educational careers. This dissertation aimed to contribute to our understanding of developments in students’ motivation for school during upper primary school and the relations between these developments and achievement growth. It furthermore aimed to investigate factors of the learning context associated with developments in motivation and achievement. More specifically, it examined how classroom composition and innovative learning (IL) are related to developments in motivation and achievement, taking into account students’ socio-economic and ethnic background, and gender.