Due to its success in PISA studies since the early 2000s, Finnish education system has received worldwide attention. The highly standardized system with a relatively low level of stratification has been praised for its capability to promote educational equality. However, recent policy changes have reduced the system’s possibilities to provide equal educational opportunities and education of uniform quality to all citizens. Within comprehensive school, the introduction of free school choice policy has created local school markets, which has led, especially in large cities, to a situation where schools have been divided into high- and low-status schools. In this chapter, the relationship between different school-level factors and students’ behavioral disengagement is analyzed. A hypothesis is that the relationship between school’s structural features, such as school size and socioeconomic composition of the student population, and students’ disengagement is mediated through process-level factors, i.e., school culture. The multilevel input-process-output model provides a conceptual framework for testing this relationship. The results verify the hypothesis only partly. The connection of school’s structural features with students’ disengagement is not mediated through school culture, but the structure and culture are at the same “hierarchical” level both contributing to the disengagement through students’ intrapersonal attitudes and experiences.